Scheduling Guide for Program Managers

SCHEDULING GUIDE FOR PROGRAM MANAGERS

October 2001

PUBLISHED BY THE DEFENSE SYSTEMS MANAGEMENT COLLEGE PRESS FORT BELVOIR, VA 22060-5565

For sale by the U.S. Government Printing Office Superintendent of Documents, Mail Stop: SSOP, Washington, DC 20302-9328 ii FOREWORD

This guide provides an introduction to scheduling intended for use by government program managers and industry program of project managers and their respective staffs. It is the third version of a 1986 publication prepared by Mr. David D. Acker, Mr. J. Stanley Baumgartner, and Mr. Michael B. Patterson. A second version, published in 1994, was prepared by Mr. William W. Bahnmaier and Mr. Paul T. McMahon.

This version addresses many of the topics contained in their earlier versions, especially those relating to the different types of scheduling techniques. The major difference between this and the previous versions is the treatment of scheduling as part of the acquisition process and the overall program management effort, particularly as it relates to the planning and control functions of program management. Scheduling is discussed in the context of the development of integrated master plans and schedules, the risk management process, and earned value management.

This guide is not intended as a detailed treatment of scheduling techniques. Instead, it is more of a primer on the subject, addressing the importance of scheduling and the application of basic scheduling techniques. It is a compilation of information from various sources, and hopefully will serve as a starting point for those who desire to delve deeper into the various scheduling techniques.

The proliferation of microcomputers has greatly enhanced the capability of managers at all levels to develop and analyze schedules. Chapter 9 provides an overview of the types of automated tools available and information on desirable features of scheduling software applications.

This document reflects the efforts of many people. Mr. William W. Bahnmaier , Mr. Paul T. McMahon , Lt Col. David Bachman, USAF, and Mr. John Kelley of the DAU/DSMC faculty provided invaluable guidance and advice. Mr. Gregory T. Caruth of the DAU/ DSMC Press was very helpful in the composition of the guide. Frances M. Battle, provided desktop publishing skills. Mr. Van Kinney, Ms. Joni Forman and Mr. Tom Parry of the OSD Acquisition, Resources and Analysis staff provided comments on the draft and overall support for the project. Special recognition also goes to the Institute for Defense Analysis team of Mr. Lou Simpleman, Mr. Jim Lloyd, Mr. George Tolis, Ms. Patti Phillips, Ms. Tina Higgins, and Ms. Yolanda Prescott, who wrote, edited, and prepared the major portions of the text.

Norman A. McDaniel William W. Bahnmaier Chair Editor Program Management and Leadership Program Management and Leadership Department Department iii iv CONTENTS

Chapter 1 INTRODUCTION ...... 1 1.1 Overview ...... 2 1.2 Purpose of This Guide ...... 2 1.3 Guide Content ...... 2 1.4 Other Sources of Data ...... 2

Chapter 2 PROGRAM MANAGEMENT AND THE ACQUISITION PROCESS ...... 3 2.1 Program Management Overview ...... 3 2.2 The Evolution of Program Management ...... 4 2.3 The Acquisition Process and Scheduling ...... 5 2.4 Risk Management and Scheduling ...... 6

Chapter 3 PROGRAM MANAGEMENT AND SCHEDULING ...... 7 3.1 Program Planning and Scheduling ...... 7 3.2 Work Breakdown Structure ...... 8 3.2.1 Integrated Master Plans/Schedules ...... 10 3.3 Program Controlling and Scheduling ...... 11 3.3.1 Earned Value Management ...... 11 3.4 Schedule Preparation ...... 13 3.4.1 Activity Definition ...... 13 3.4.2 Activity Sequencing ...... 14 3.4.3 Activity Duration Estimating ...... 14 3.4.4 Schedule Development ...... 15 3.4.5 Schedule Control ...... 15 3.5 Schedule Risk ...... 16 3.6 Summary ...... 17

Chapter 4 SCHEDULE TYPES AND THEIR EVOLUTION ...... 19 4.1 Introduction ...... 19 4.2 Schedule Types ...... 19 4.2.1 Gantt and Milestone Charts ...... 19 4.2.2 Network Schedules ...... 21 4.2.3 Production Schedules...... 23 4.3 Summary ...... 24

Chapter 5 GANTT AND MILESTONE CHARTS ...... 25 5.1 Description ...... 25 5.2 Constructing Gantt and Milestone Charts ...... 31 5.3 Gantt and Milestone Chart Advantages and Disadvantages ...... 32 5.3.1 Advantages ...... 32 5.3.2 Disadvantages ...... 32 5.4 How and When Gantt and Milestone Charts Are Employed ...... 32

v 5.5 Summary ...... 33

Chapter 6 NETWORK SCHEDULING ...... 35 6.1 Description ...... 35 6.1.1 PERT ...... 36 6.1.2 CPM ...... 37 6.1.3 PDM ...... 38 6.2 Network Scheduling Advantages and Disadvantages ...... 41 6.2.1 Advantages ...... 41 6.2.2 Disadvantages ...... 41 6.3 How and When To Network Schedules Are Employed ...... 41 6.3.1 PERT Example ...... 42 6.3.2 CPM Example ...... 44 6.3.3 PDM Example ...... 46 6.4 Network Scheduling When Resources Are Limited ...... 49 6.5 Summary ...... 51

Chapter 7 PRODUCTION SCHEDULING ...... 53 7.1 Description ...... 53 7.1.1 Objective Chart ...... 54 7.1.2 Production Plan Chart ...... 54 7.1.3 Program Status Chart ...... 56 7.1.4 Line of Balance ...... 56 7.2 How and When To Use the Line of Balance Techniques ...... 57 7.2.1 General...... 57 7.2.2 Analysis ...... 57 7.3 Line of Balance Advantages and Disadvantages...... 58 7.3.1 Advantages ...... 58 7.3.2 Disadvantages ...... 58 7.4 Summary ...... 58

Chapter 8 TIME MANAGEMENT ...... 59 8.1 Time Management and the Program ...... 59 8.1.1 Time Reserve ...... 59 8.1.2 “Now” Schedule ...... 59 8.1.3 Value of Time ...... 60 8.2 Time Management and the Program Manager ...... 62 8.3 Summary ...... 63

Chapter 9 AUTOMATED SCHEDULING TOOLS ...... 65 9.1 Automated Planning Aids ...... 65 9.2 Functional Characteristics and Features ...... 66 9.3 Evaluating Project Management Software Projects ...... 68 9.4 Finding Out More ...... 70

vi APPENDIX A INTEGRATED MASTER SCHEDULE ...... 71

APPENDIX B TIME ROBBERS ...... 77

APPENDIX C GLOSSARY ...... 79

APPENDIX D BIBLIOGRAPHY ...... 83

FIGURES 3-1 Generic Aircraft System WBS ...... 9 3-2 IMP/IMS Sample ...... 10 4-1 Gantt Chart Example ...... 20 4-2 Milestone Chart Example ...... 21 4-3 Network Schedule Example ...... 22 5-1 Example Gantt Chart Symbols ...... 25 5-2 Example Gantt Chart ...... 26 5-3 Example Milestone Chart Symbols ...... 27 5-4 Example Milestone Chart ...... 28 5-5 Example Combination Chart ...... 29 5-6 Gantt Chart with Amplifying Information ...... 30 6-1 Beta Distribution with PERT Time Estimates ...... 37 6-2 Example PDM Relationships/Constraints ...... 39 6-3 Example PDM Constraints with Lag Time ...... 40 6-4 Example PDM Activity Node ...... 40 6-5 PERT Example ...... 42 6-6 PERT Example with Slack Time ...... 43 6-7 CPM Example ...... 44 6-8 PDM Example ...... 47 6-9 PDM Example—Example and Late Start and Finish Times ...... 47 6-10 PDM Example with Lag Time ...... 48 6-11 Network Schedule with Constrained Resources ...... 49 6-12 Personnel Loading Chart ...... 50 6-13 Revised Personnel Loading Chart ...... 51 6-14 Revised Network Schedule with Constrained Resources ...... 52 7-1 Line of Balance Technique ...... 55 8-1 Total Cost Analysis for Selecting “Optimum” Program Duration ...... 60 9-1 On-Screen Data Entry Using Gantt Chart Feature (AEC Software Fast Track Schedule) 68

TABLES 6-1 CPM Example Time Estimates ...... 46 9-1 Project Management Software Functions and Criteria ...... 69

vii viii ix 1 INTRODUCTION

1.1 OVERVIEW Effective scheduling supports the following key program management activities: In its simplest form, a schedule is a listing of activities and events organized by time. • Provides the basis for effective com- In its more complex form, the process ex- munications within the government team amines all program activities and their re- and with contractors, lationships to each other in terms of realistic constraints of time, funds, and people, • Identifies a baseline for program status i.e., resources. In program management monitoring, reporting, and program control, practice, the schedule is a powerful planning, control, and communications tool that, • Facilitates management, and when properly executed, supports time and cost estimates, opens communications • Provides the basis for resource analysis among personnel involved in program ac- and leveling, exploration of alternatives, tivities, and establishes a commitment to and cost/time tradeoff studies. program activities. On the other hand, poor scheduling can A key aspect of program management plan- adversely impact a program in a number ning, scheduling is integral to a program’s of areas. Haphazard schedules make it acquisition strategy and to risk manage- difficult, at best, to determine a realistic ment, financial, and technical management completion date and to efficiently allo- plans. In addition, scheduling is an impor- cate resources to the entire program. This tant element of the other management func- creates financial problems—escalation of tions: organizing, staffing, controlling, and costs, increased support costs, delayed leading. For example, controlling is per- return on investment, funding cuts, or formed to keep abreast of program execu- program termination. tion. To achieve this goal, it is necessary to know whether the program is behind, on, Since scheduling is a powerful planning, or ahead of schedule, and what adjust- control, and communications tool avail- ments are necessary to keep the program able for program management, PMs must on schedule once it’s back on track. have a good working knowledge of scheduling practices and applications (such as Why do Program Managers (PMs) sched- Gantt, milestone, and network schedules) ule? The simple answer is they need a road in order to achieve program goals. PMs map for all program players. In reality, will not always have to construct detailed scheduling can accomplish far more than schedules, but they must be able to under- providing a list of activities and times. stand and analyze schedules created by

1 others (e.g., contractors) to successfully the various types of schedules and how manage a program. Since scheduling is an and why they evolved. This chapter is a intrinsic and indispensable element of the precursor for Chapters 5, 6, and 7, which management process, it is treated within present a more detailed discussion of the context of program management. the key schedule types. These chapters focus on Gantt and milestone schedules, 1.2 PURPOSE OF THIS GUIDE network schedules, and production schedules. This guide is an introduction to scheduling. It is meant for people who already Chapter 8 introduces the concept of time have some experience in program man- management as it relates to the program agement and those who seek to learn more and to the PM. Chapter 9 presents the about the subject. It is not a detailed subject of automated project planning tools treatment of the subject, but instead, ex- and summarizes some of the desirable fea- plains how scheduling fits into the overall tures of currently available software prod- program management effort and how to ucts. In addition to an overview describing accomplish schedule planning. It also il- the types of automated tools available, this lustrates different scheduling concepts chapter provides some suggestions on how and techniques and how they can be ap- to find and evaluate the latest products. plied and analyzed to manage effectively. The chapter concludes with a summary of Finally, it is intended as a road map to information sources that will be useful for other useful and more comprehensive further inquiry. documents and texts on the subjects of project management, planning, and sched- 1.4 OTHER SOURCES OF DATA uling that are available in the literature. As previously noted, this guide is intended 1.3 GUIDE CONTENT as a primer. There is a considerable body of literature on the subject of scheduling. In order to provide a suitable context for Much of it is of an academic nature not the topic of scheduling, Chapter 2 pro- specifically keyed to defense acquisition. vides an overview of both program man- A number of these texts are listed in the agement and the acquisition process and Bibliography Appendix of this guide. Ad- the role scheduling plays in each. ditionally, an enormous amount of rel- evant information can be secured by search- Chapter 3 expands on the role of scheduling the web using some of the popular ing in program management and addresses search engines. the following topics: work breakdown Of particular use to PMs is the Defense structure, integrated master plans and Acquisition Deskbook, available on the schedules, and earned value management. Internet (http://www.deskbook. osd.mil). It concludes with a discussion of schedule The Deskbook includes a database contain- preparation and schedule risk. ing mandatory and discretionary policy documents, Department of Defense and Chapter 4 introduces the topic of schedul- component discretionary practices, soft- ing techniques with a general discussion of ware tools and descriptions, front-line wisdom and advice, and sample formats. 2 2 PROGRAM MANAGEMENT AND THE ACQUISITION PROCESS

2.1 PROGRAM MANAGEMENT For purposes of this guidebook, Program OVERVIEW Management consists of the planning, organizing, staffing, controlling, and leading The Department of Defense (DoD) consid- (POSCL) management functions. Other ers program management to consist of the functions sometimes included in a pro- tasks and activities that must be done in gram management context are scheduling, order to design, develop, field, and sup- budgeting, monitoring, directing, and port a weapons system. DoD directives maintaining consensus and support. For describe an Acquisition Program as: “A this guidebook, these latter functions are directed, funded effort that is designed to considered subcategories of the basic five provide a new, improved, or continuing functions, when appropriate. weapons system or automated information system (AIS) capability in response to • Planning addresses the program mis- a validated operational need.”1 DoD con- sion, objectives, goals, and strategy and siders the “program” to include the ele- includes all management activities that re- ments of the acquisition process, such as sult in selection of a course of action. the planning, programming, and budgeting process, and the design, development, • Organizing considers the resources in- and production of the system. Practically volved and how are they related. This func- speaking, a DoD program consists of a tion addresses the alignment of people, combination of organizational resources, funds, equipment, facilities, etc., and the assembled to create a weapons system to structure of the organization in order to meet a specific operational requirement. meet program goals; it identifies:

Four key considerations typically involved − Authority—The power to make final in a program are: decisions

• Cost to produce the system, − Responsibility—The obligation to perform assignments • Time required to complete the effort, − Accountability—The state of being • Capability/technical performance re- answerable for the completion of an quired to meet needs, and assignment.

• Contribution of the system to the over- • Staffing addresses the qualifications all defense operational and strategic plans. and special skills that may be required

3 for persons assigned to each position in felt the need to predict the cost, schedule, the program and the time phasing of as- and performance of its new systems. Mili- signments. tary organizations (predecessors of current “acquisition” organizations), in conjunc- • Controlling is the function during which tion with defense contractors, developed the manager monitors, measures, evalu- much of the early theory and practices of ates, and corrects program activities to en- program management as new technolo- sure that actual operations conform to gies emerged. plans. The use of “task teams” or program teams • Leading is the process whereby one and other organizational entities led to the individual exerts his/her influence over emergence of a program management phi- others in a group. Directing, an element of losophy for integrating activity in organiza- leadership, is the process of implement- tions. As the program management disci- ing, through the talents of others, the plans pline evolved, organizations developed to meet program objectives. This includes special techniques for planning, organiz- training, supervising, delegating, motivat- ing, staffing, controlling, and leading pro- ing, counseling, and coordinating. grams to integrate those activities from a focal point in the organizational structure. In a broad sense, the planning phase in- Moreover, program management ad- cludes the tasks associated with defining dressed the elements of technical perfor- the work requirements, specifying the quan- mance, cost, and schedule on a continual tity and quality of work, identifying re- rather than one-time basis in the evolution sources, and organizing them to best carry of a program and considered them within out the program. Likewise, the manage- the context of an organization’s operational ment or execution phase includes the tasks of (short-term) and strategic (long-term) monitoring progress, comparing actual to objectives. predicted outcomes, analyzing the impact of differences between planned and actual DoD has recently improved management achievements, and adjusting the program with the introduction of the concept of as necessary. Integrated Product and Process Develop- ment (IPPD) and Integrated Product Teams 2.2 THE EVOLUTION OF (IPTs). IPPD integrates all acquisition ac- PROGRAM MANAGEMENT tivities to optimize system development, production, and deployment. Key to the Formal program management came to the success of this concept are the IPTs, com- forefront in the late 1950s. The need to posed of qualified and empowered repre- develop and implement a management sentatives from all appropriate functional approach to manage large-scale military disciplines who work together to identify systems, both weapons and support sys- and resolve issues. IPTs are the founda- tems, stimulated the government and aero- tion for program management. One of the space industry to devise the means to plan tenets of IPPD is the use of event-driven and execute complex programs. As the scheduling, which relates program events cost of weapons systems increased and the to their accomplishment and accomplish- intensity of the Cold War grew, DoD also ment criteria. Its use reduces risk by 4 ensuring that product and process matu- support each milestone decision by de- rity is incrementally demonstrated prior to scribing activities and events planned for beginning follow-on activities. the upcoming phase and relating the accomplishments of that phase to the 2.3 THE ACQUISITION PROCESS program’s overall, long-term objectives. AND SCHEDULING The acquisition strategy is first formally approved and published at MSI, Program For the management of programs, the DoD Initiation. It provides a master schedule for acquisition process provides a framework research, development, test, production, that consists of a series of phases and mile- fielding, and other activities essential to stones. The phases are a logical means of program success. This master schedule progressively translating broad mission also serves as the basis for formulating need statements into well-defined system- functional plans and schedules. specific requirements and ultimately into operationally effective, suitable, and sur- As a program evolves through subsequent vivable systems. Each phase is designed, phases, new information becomes avail- among other things, to manage/reduce the able that permits refinement of schedules risks, ensure affordability, and deliver the and assignment of resources. Understand- system to the user as soon as possible. ing of program risk becomes more specific Milestones are the points in time where as the system under development is de- decision makers evaluate the status of the fined, thereby allowing identification of program and determine if the program risk-handling initiatives and their effect on should proceed to the next phase. Prudent schedule. Schedule considerations are an consideration of schedule implications is integral part of any Source Selection pro- important in all phases of a program. cess, from preparation of the Request for Proposal (RFP) through proposal evalua- Milestone Decision Authority (MDA) and tion. After contract award, the schedule Service acquisition officials are encouraged serves as a basis to determine progress and to tailor programs to eliminate phases or assess the need for management action. activities that result in little payoff in terms of fielding time or cost. To effectively Government developers should design their tailor a program, managers must under- contracts with industry to allow time for stand scheduling, resource availability and milestone decisions, permit demonstration allocation, and the risk associated with the of exit criteria in time to support milestone tailoring. reviews and to reflect expenditure of money with the program’s funding profile. A good An acquisition strategy defines the busi- acquisition strategy allows fiscal control ness and technical management approach without delaying the acquisition decisions to meet objectives within schedule and or contracts while adequately considering program constraints. A primary goal is to risk. In other words, it reflects thoughtful minimize the time and cost of satisfying a schedule and resource planning. valid need, consistent with common sense and sound business practices. A PM pre- As a key element of the planning proess, PMs pares a preliminary acquisition strategy at must update the schedule as more is learned Milestone 0 and updates the strategy to about the program and as changes occur. 5 With each new update, program cost, time, Risk management and scheduling are and requirements may change. PMs must closely tied. Consideration of one requires respond by changing the mix and level of a reassessment of the other. For example, resources and continuously updating the in creating the strategy and plans to handle program plan and the schedule as needed. program risk, a PM must consider how the approach affects the pro- 2.4 RISK MANAGEMENT AND gram schedule. Similarly, any tradeoffs SCHEDULING between cost and performance must take into account schedule implications. Con- DoD defines risk management as “the act versely, any change to the program sched- or practice of controlling risk. It includes ule must consider the impact on the overall risk planning, assessing risk areas, devel- program objectives and on cost and perfor- oping risk-handling options, monitoring mance. The challenge is to develop a plan risks to determine how risks have changed, that balances risk, cost, schedule, and per- and documenting the overall risk manage- formance. ment program.”2 As part of their responsibility to manage risk, PMs must consider Schedule risk is defined as the likelihood risk in their planning and scheduling prac- and consequences of failing to meet the tices. Risk management is concerned with program schedule, and it is an integral part the identification of uncertainties that of program risk. This topic is covered in threaten cost, schedule, and performance Chapter 3. objectives, and the development and implementation of actions to best deal with those uncertainties.

ENDNOTES

1 DoDD 5000.1, Defense Acquisition, March 15, 1996. (Being revised and updated as of 1 January 2000) 2 Ibid.

6 3 PROGRAM MANAGEMENT AND SCHEDULING

As discussed in the previous chapters, of the program that functional plans will scheduling is one of the most powerful lay out in greater detail and reflects the tools available to the PM, and its effective strategy that will be followed to meet pro- application is essential to program suc- gram objectives and to handle risk in the cess. While it is a key element in perform- program. The acquisition strategy in- ing all program management functions, it cludes a program structure/schedule is also critical to the accomplishment of which depicts a visual overview and pic- planning and controlling management ture presentation of the acquisition strat- functions. This chapter discusses schedul- egy. This schedule is a single diagram ing in the context of these two functions similar to the diagram shown in Figure 3-3, and addresses the essential elements and and defines the relationship among acqui- considerations in schedule planning. sition phases, decision milestones, solici- tations, contract awards, systems engineer- 3.1 PROGRAM PLANNING AND ing design reviews, contract deliveries, test SCHEDULING and evaluation activities, production re- leases, and operational deployment objec- Program planning is the process of deter- tives. It includes quantities to be procured mining what needs to be accomplished, by and delivered by fiscal year by phase in whom, when, and under what resource terms of prototypes, engineering constraints. It is arguably the most impor- developmemt models, low-rate intitial pro- tant of the program management functions. duction and full-rate production. The pro- Without a sound and comprehensive plan, gram structure/schedule is a key decision it is virtually impossible to develop a mean- review/milestone document; it summa- ingful budget, effectively organize and staff rizes the program and is built from many the program office, direct the actions of the other more detailed schedules found in program office, or monitor and control the functional plans such as test and evalua- program. In addition to determining the tion, contracting, etc. It is sometimes re- “what, where, who, with what, and when” ferred to as the Master Program Schedule of a program, planning also helps to iden- (MPS). In addition to this top level struc- tify risk areas and ways to handle the risk, ture/schedule, the PM may deem it neces- and establishes the program baselines. sary to have more detailed program management Integrated Master Plans (IMP) and There are a number of products of the Integrated Master Schedules (IMS) pre- planning process. Among them are: pared and submitted by the contractor • Acquisition Strategy—This is the com- during the proposal process. See the DSMC Acquisition Strategy Guide1 for information prehensive, integrated plan the program on structuring, developing, and executing will follow. It provides an overall concept an acquisition strategy. 7 • Functional Plans—These are the de- Scheduling is a critical element in the plan- tailed plans that lay out the approach to ning process. In addition to being an out- be taken in the different functional areas. put of the process as discussed above, it Examples include: the Test and Evalua- also contributes to the development of the tion Master Plan (TEMP) and Command, other outputs. The early involvement of Control, Communications, Computers, and people who are knowledgeable and experi- Intelligence (C4I) Support Plan, which are enced in scheduling techniques can contrib- required; and the Systems Engineering ute to the effective translation of strategic Master Plan (SEMP), Logistics Support concepts and ideas into detailed logic dia- Plan (LSP), etc., which are optional. grams, depicting the program activities and relationships among activities. This • Work Breakdown Structure (WBS)— can be very useful in developing budget The WBS provides a basic framework for and detailed functional plans, especially identifying each element of a project in in identifying the required resources and increasing levels of detail. In essence, it leveling them throughout the activities. describes the way work is performed. The WBS also provides a coherent method for The WBS and the IMP/IMS are important reporting progress toward plan goals. concepts used in the scheduling process and are described in more detail in the • Integrated Master Plan (IMP)—The following sections. IMP is an event-based plan depicting the overall structure of the program and the 3.2 WORK BREAKDOWN STRUCTURE key processes, activities, and milestones. It defines accomplishments and criteria for During the 1960s, the impetus to develop a each event. tool to help project managers define a project in a cohesive way gave rise to the • Integrated Master Schedule (IMS)— development of the WBS. WBS use has not The IMS shows the detailed tasks and been confined to the DoD and its contrac- timing for events in the IMP and depicts tors; rather, it is now used in many com- the logical progression of events through- mercial enterprises. Several years after the out the program. These tasks should be emergence of the WBS concept, DoD pub- directly traceable to the IMP and the WBS. lished a WBS standard for DoD acquisition organizations as well as their contractors to • Schedules—A series of schedules are use: MIL-STD-881B. This standard has been developed during the planning process, superseded by a handbook, MIL-HDBK- all of which are derived from the IMS. 881, dated 2 January 1998. It contains much These schedules are developed to show of the same information as its predecessor the details required to complete key activi- but is not directive in nature and is for ties and milestones. guidance only.

• Budget—The budget reflects the cost MIL-HDBK-881defines a WBS as: of the integration of the scope, schedule, and resource plan for accomplishing the • A product-oriented family tree com- work. posed of hardware, software, services, data, and facilities. The family tree results from 8 Prime Mission System

Level 1 Level 2 Level 3 Aircraft System Air Vehicle Airframe Propulsion A/V Application S/W A/V System S/W Navigation/Guidance Central Computer Fire Control Data Display and Controls Survivability Reconnaissance Automatic Flight Control Central Integrated Checkout Antisubmarine Warfare Armament Weapons Delivery Auxiliary Equipment Systems Eng/ Program Mgmt System Test and Evaluation Development Test and Evaluation Operational Test and Evaluation Mock-ups Test and Evaluation Support Test Facilities

Training Equipment Services Facilities

Data Technical Publications Engineering Data Management Data Support Data Data Depository

Peculiar Support Test and Measurement Equipment Equipment Support and Handling Equipment

Common Support Test and Measurement Equipment Equipment Support and Handling Equipment

Operational/Site Activation System Assembly, Installation and Checkout on Site Contractor Technical Support Site Construction Site/Ship/Vehicle Conversion

Industrial Facilities Construction/Conversion/Expansion Equipment Acquisition or Modernization Maintenance (Industrial Facilities)

Initial Spares & Initial Spares and Repair Parts Repair Parts Figure 3-1. Generic Aircraft System Program WBS systems engineering efforts during the ac- high cost or high risk. In that case, the WBS quisition of a defense materiel item. should be taken to a lower level of definition. • A WBS displays and defines the product, or products, to be developed and/or WBS's apply to seven specific categories of produced. It relates the elements fo work defense materiel systems: aircraft; elec- to be accoomplished to each other and to tronic/automated software; missile, ord- the end product. nance; ship; space; and surface vehicle. The WBS should be developed and main- • A WBS can be expressed down to any tained based on the systems engineering level of interest. However, the top three efforts throughout the system’s life cycle. levels are as far as any program or contract needs to go unless the items identified are Figure 3-1 is an example of a level 3 program 9 Requirement WBS Elements SOW Task

System Specification 1000 Air Vehicle 3.1 Air Vehicle (WBS 1000) 1100 Airframe Design, develop, produce 1000 Air Vehicle 1110 Wing and verify, complete air 1100 Airframe vehicles, defined as airframe propulsion, avionics and Wing 11n other installed equipment.

Integrated Master Plan

Management Plan Events Accomplishment Criteria 1. Preliminary Design PDR 1. a. Duty Cycle Defined 2. Review b. Preliminary Analysis Complete

Integrated Master Schedule

19XX 19XY 19XZ Program Events PDR CDR Detailed Tasks 1. Preliminary Design Complete 2. Duty Cycle Defined

Figure 3-2. IMP/IMS Sample

WBS for an aircraft system. The WBS ap- provides the basis for development of sub- proach provides a powerful technique for ordinate IMPs and other functional plans. scoping a project in a manner that provides It also identifies those events and activities management with insight into project re- that will be included in the IMS. quirements and performancefrom the very top, or systems level, to the lowest The IMS is a networked multi-layered level of definition of a work product. Plan- schedule generated by the contractor that ning work using the WBS approach serves begins with all identified IMP events, ac- as the basis for both estimating and sched- complishments, and criteria. It shows the uling resource requirement. expected start and finish dates of these events. It contains all contractually re- 3.2.1 Integrated Master Plans/ quired events/ milestones such as reviews, Schedules tests, completion dates, and deliveries specified in the program WBS. The IMP is a very effective tool of program management. It is the contractor's event- The IMP is prepared by the contractor based plan for accomplishing the State- during the proposal process. It is main- ment of Objectives (SOO) and Statement of tained by the government program office Work (SOW). It identifies the key activi- and contractor through a collaborative ef- ties, events, milestones, and reviews that fort involving all the program “stakehold- make up the program. A program IMP is ers.” In some cases, a preliminary IMP prepared initially by the contractor and may be developed by the government,

10 with industry input, during pre-solicita- corrective action. However, considering tion. The IMP defines contract requirements schedule information alone can be mis- stated in the RFP and contractors use it to leading. Successful management requires develop the IMS and detailed functional the integration of the technical, schedule, schedules. These integrated schedules tie and cost aspects of a program. Thus, some together all program tasks by showing their form of integrated performance measure- logical relationships and any constraints ment is needed for monitoring and control- controlling the start or finish of each task. ling a program. The concept of earned value This process results in a hierarchy of re- management provides such a capability. lated functional and layered schedules derived from the WBS that can be used for 3.3.1 Earned Value Mangement monitoring and controlling program progress. An example (suggested format) Earned Value Management (EVM) is the of an IMP/IMS for an aircraft development use of an integrated management system program is depicted in Figure 3-2. The IMS that coordinates work scope, schedule, and should be expanded down to the level of cost goals and objectively measures pro- detail appropriate for the scope and risk of gress toward these goals.2 The purpose of the program. Programs with high risk EVM is to provide contractor and gov- should show more detail in the IMS to ernment PMs with accurate data to moni- provide the visibility necessary to manage tor program execution. It is also intended risk. A more detailed discussion of IMS's is to provide an adequate basis for sound contained in Appendix A. A Data Item contractor and government decision mak- Decription (DID) has been developed by the ing by requiring that the contractor’s inter- Department of Defense for the IMS; the iden- nal management control systems produce tification number is DI-MISC-81183A. This data that: (1) indicate work progress; (2) properly relate cost, schedule, and techni- DID is at Tab 1 to Appendix A. cal accomplishments; (3) are valid, timely, and able to be audited; and (4) provide 3.3 PROGRAM CONTROLLING DoD component managers with informa- AND SCHEDULING tion at a practical level of summarization. The controlling function contains all those The DoD earned value process holds the activities that a program manager under- contractor responsible for effective imple- takes in attempting to ensure that the ac- mentation of an EVM system. DoD does not tual program conforms to the developed prescribe a specific EVM system for con- plan, to include the implementation of nec- tractors to use; instead, it has established a essary action to get the program back on set of criteria that the contractors’ systems the plan if possible. To control a program, must meet to be acceptable. The require- the PM needs the means to monitor pro- ment to use an EVM system that meets the gram progress against the established plan, criteria is dependent on the type and size or the program baseline. In its simplest of the contract. DoD Regulation 5000.2-R form, the program schedule can serve as a defines the contracts that must use such an baseline against which to measure progress. EVM system as well as the criteria for an If there are indications that an activity is acceptable system. For contracts that do falling behind schedule, this information can be used by the manager as a basis for 11 not meet these thresholds, contractor man- Analysis of these data points over time agement information is provided to the also identifies trends that may affect or government using a Cost/Schedule Status impact the future performance for the re- Report (C/SSR). This report should be mainder of the contract. This is important; based on an underlying management sys- it enables PMs to isolate causes of recur- tem that uses an earned value approach for ring variations and to take alternative ac- tracking progress. Such a system does not tions that will improve performance. Quan- have to meet the EVM criteria of DoD titative techniques can also be applied to 5000.2-R; however, the government should EVM data to predict program performance negotiate with the contractor to ensure that at completion in terms of cost and sched- the system does emphasize earned value ule. The DSMC EVM Textbook3 provides methodology. detailed information on the application of EVM techniques. Basically, earned value relates resource planning to schedules and to technical per- Success of EVM techniques is dependent on formance requirements. All work (identi- several things, not the least of which is fied in the Program and Contract Work effective and accurate contractor schedul- Breakdown Structures) is planned, bud- ing. EVM system criteria do not require geted, and scheduled in time-phased contractors to use specific scheduling tech- “planned value” increments constituting a niques. However, they do seek formality, performance measurement baseline. As consistency, and discipline throughout the work is performed, it is “earned” on the scheduling process. The contractor's sched- same basis as it was planned, e.g., in bud- uling system: geted dollars or labor-hours. Planned value [budgeted cost of work scheduled (BCWS)] • Provides a summary or master sched- compared with earned value [budgeted cost ule and related subordinate schedules of work performed (BCWP)] measures the showing vertical traceability from the mas- dollar volume of work planned versus the ter to the detailed schedules equivalent dollar value of work accomplished. The difference, if any, is termed • Identifies key milestones and activities the “schedule” or “accomplishment” vari- and indicates significant constraints and ance. Earned value (BCWP) compared relationships with the actual cost of the work performed (ACWP) provides an objective measure- • Provides current status and forecast of ment of cost performance. Any difference completion dates of scheduled work that is called the cost variance. enable comparison of planned and actual status of program accomplishments The three data points—BCWS, BCWP, and ACWP—are outputs of the EVM system and • Establishes a schedule baseline are provided to the government on a monthly basis. They, along with the schedule and cost • Provides horizontal traceability show- variances, provide the basic information ing interrelationships among various ac- needed to determine program status at a tivities. given time, and to identify the elements that are driving each of the variances.

12 The scheduling baseline usually con- more detailed schedule information. The sists of a hierarchy of vertically inte- schedule for the out-year phases will be grated schedules, with each lower-level adjusted based on the most current infor- schedule more fully identifying and ex- mation. However, this should not be taken panding the tasks necessary to meet the as a license to make easy changes in the program’s objectives. Generally, three sets schedule. Every effort should be made to of schedules are prepared: maintain the original schedule.

• Master Schedule (MS)—The top-level In all programs, there will always be a schedule that summarizes key program requirement to make tradeoffs between activities and milestones and depicts the cost, schedule, and performance. Cost in- logical progression of events throughout a cludes all resources—people, money, contract. Program Structures/Master Pro- equipment and facilities. Performance in- gram Schedules developed by the govern- cludes quality and supportability param- ment PM reflect information contained in eters. The best schedule supports the best the contractor's Master Schedule. tradeoff between these competing demands, taking into account the risks that • Intermediate Schedules—The sched- are associated with each tradeoff and the ule that ties the MS to the detailed sched- impact on the overall program. ules. It allows for rollup of detailed schedules to summary levels that are useful for The preparation of program schedules management. should be done within a formal structure. The procedures to be followed should be • Detailed Schedules—The schedules at specified, to include such things as soft- the control account or work package level. ware applications to be used, the formats Work packages must be distinguishable for displays, and the type of symbols to be from each other and must include definite used. Also, clear lines of authority and start and completion dates. They are pre- responsibility should be established. The pared by the contractor with government remainder of this section discusses the logi- concurrence. cal steps that should be followed in preparing schedules, to include sources of 3.4 SCHEDULE PREPARATION information, tools and techniques, and the outputs of the steps. These steps are based As stated earlier, scheduling is a critical on those described in the Program Man- element of the planning process. Con- agement Institute’s Guide to the Program versely, planning is critical to the devel- Management Body of Knowledge.4 While they opment of effective schedules. Near-term present a somewhat different approach scheduling can and should be accom- than the IMP/IMS method, they have ge- plished in sufficient detail to support neric applicability over the range of plan- management at each level. Far-term, or ning methods. rolling-wave, scheduling will be less pre- cise, accounting for the alternative paths 3.4.1 Activity Definition that the program may take. As the program approaches each phase, the sched- This step involves the identification and ule for that phase will be fleshed out with definition of those activities that must be 13 accomplished to achieve the objectives. There are several inputs to this step: The WBS is a logical source for such descriptions. If a WBS is not available, • The activity list developed in the activ- more planning must be done in order to ity definition step, identify project activities clearly. Other inputs to the definition step are the pro- • The product description and character- gram scope, historical information, pro- istics, gram constraints and assumptions, and events required by the Planning, Program- • Mandatory constraints/dependencies, ming, and Budgeting System (PPBS), the such as the fact that a prototype must be requirements generation system, and DoD fabricated before it can be tested, acquisition management process. • Discretionary constraints/depend- Decomposition and templates are tech- encies developed by the program manage- niques commonly used in activity defini- ment team based on “best practices” or tion. Decomposition involves the succes- specific sequences desired by management, sive breakdown of program elements into smaller, more manageable components, • External dependencies, such as avail- which eventually describe the activities to ability of test sites, and be scheduled. This technique is essentially the same used in WBS development. • Other constraints and assumptions. A template is an activity list or WBS element from another similar program that A number of tools and techniques are use- can serve as a model for the current pro- ful in developing the logic diagrams that gram and provide a starting point for de- reflect the desired activity sequencing. fining specific activities. They include various network scheduling techniques that are discussed in Chapters 4 The primary output of this step is the activ- and 6. In addition, a number of scheduling ity list, which should contain a complete software programs develop activity se- description of each of the activities neces- quencing. Their selection and use are dis- sary to complete the program. This list cussed in Chapter 9. should be linked to the WBS, which should be reviewed and revised/clarified as nec- The output of this step is a network dia- essary to incorporate changes resulting gram that reflects the sequence of activities from the activity definition process. Sup- based on the inputs described above. This porting details for each activity, such as diagram should be augmented with a constraints and assumptions, should also narrative description of the sequencing ap- be developed and documented. proach and a detailed discussion of any unusual or complex sequences. Activity 3.4.2 Activity Sequencing lists should be reviewed and revised to reflect any changes necessitated by activity This step involves the accurate identifica- sequencing. tion of constraints/relationships among activities and establishing the order in which 3.4.3 Activity Duration Estimating the activities will be accomplished. Activity duration estimating is the determi- 14 nation of the time required to complete the requirements and availability, calendars activities that make up the program. This that show when work can be performed, is one of the most difficult aspects of sched- constraints, assumptions, and risk. ule development and should be performed by people who are most familiar with the The output of this step is a set of sched- activity. Two key inputs to the estimation ules for the program. These include the process are the resources required and as- master program schedule and the support- signed for the activity and the capabilities ing detailed schedules, which should re- of the resources assigned. Historical infor- flect the best balance possible between com- mation from other programs and from competing demands of time and resources. mercial databases can also be helpful in They should also take into account the risk developing accurate estimates. associated with time, cost, and performance tradeoffs and the impact on the overall The following techniques are commonly program. used in estimating activity durations: A number of techniques and tools are useful • Expert judgment guided by historical in developing schedules, many of which are information, contained in various scheduling software applications. Many of these applications • Analogous estimating based on expe- contain the capability to perform various rience of similar programs, types of mathematical analyses to calculate theoretical start and finish dates for each • Parametric estimating based on formu- activity based on the overall sequencing of las describing relationships among pro- the program activities. Two of the more gram parameters and time, and commonly known analysis techniques are critical path method (CPM) and the Pro- • Use of simulation to develop distri- gram Evaluation and Review Technique butions of probable duration of each (PERT). They are discussed in greater activity. detail in Chapter 6.

The output of this step is an estimate of the Other scheduling development techniques likely amount of time to complete each that are commonly used focus on schedule activity. These estimates should also in- development in light of resource (time, clude a range of possible values, e.g., 3 people, funds, material) constraints. These weeks ± 1 week, and a clear statement of techniques provide the means to manage the the assumptions made in the estimation affect of these constraints through the com- process. pression of activity duration and the leveling of resources throughout activities. Schedule 3.4.4 Schedule Development compression and resource leveling are discussed in more detail in Chapter 6. This step involves the development of realistic start and finish dates for each activity. An iterative process, schedule 3.4.5 Schedule Control development takes into account activity sequencing, duration estimates, resource The final step in the schedule preparation 15 process is to identify schedule variations and ule variations, their evaluation, and the to manage actual changes to the developed development of corrective actions should schedules. A schedule change control sys- be documented and made readily avail- tem that defines the procedures by which able to members of the program’s man- changes can be made should be established agement team, and to other programs. and integrated into the program’s overall change control system. The schedule 3.5 SCHEDULE RISK change control system should address such things as the methods of schedule perfor- In Chapter 2, we discussed the relation- mance tracking and the approval process ship between risk management and pro- for authorizing changes. The need for sched- gram scheduling. In this section, we dis- ule changes can be caused by a number of cuss the risk associated with the program factors, to include: schedule. Uncertainty exists in every schedule. It is impossible to predict, with • Failure to achieve planned dates for complete confidence, the length of time specific activities or events, necessary to complete an activity, meet a milestone, or deliver a system. Little in- • Internal program management assess- formation exists in the early phases of a ment and replanning, and program, and planners must rely on personal experience and the estimates of ex- • External direction, such as reallocation perts. As a program progresses through of funding. the acquisition cycle, more information becomes available. Schedules developed in the latter phases of a program are based When evaluating these factors, it is im- on more information and analyses, but portant to determine what, if any, sched- they still lack complete certainty. Uncer- ule change is necessary. For example, if tainty introduces the element of risk in the an activity that is not on the critical path is planning process. Schedule risk is the not completed as planned, it may not have likelihood of failing to meet schedule plans any effect on the overall program sched- and the effect of that failure. ule. Consequently, it may not require any significant schedule change. When creating a schedule, or when determining overall program risk, the PM must The schedule change control system assess the risk associated with the sched- should also include procedures for imple- ule. One technique for assessing this sched- menting schedule changes. Such proce- ule risk involves estimate contributions dures should address the requirement to for each activity’s duration and aggregat- keep all program stakeholders, especially ing these distributions using a Monte Carlo the users, advised of any significant sched- simulation or other analytical tools. The ule changes. They should also address the resulting program-level schedule is then process for adjusting the schedule baseline analyzed to determine the actual sched- and the overall program plan when neces- ule risk and to identify the schedule risk sary schedule changes are severe. The drivers. change control system can also serve as a good database of lessons learned. Conse- This technique uses a range of times that it quently, information concerning sched- will take to complete each activity instead 16 of single-point estimates. This approach and budgets and to identification and allo- results in a more realistic estimate of sched- cation of required resources throughout ule risk because it accounts for much of the program activities. During this phase is uncertainty inherent in the use of single- developed a set of integrated multi-lay- point estimates. Their use invariably leads ered schedules that tie together all pro- to underestimating the time required to gram activities, showing their logical rela- complete the program and, therefore, tionships and any constraints. The level of schedule overruns, primarily because the detail developed for these schedules de- point estimates do not adequately address pends on program scope and risk. This the uncertainty inherent in the individual process provides a hierarchy of functional activities. and layered schedules that can be useful in monitoring and controlling program This range of values for each activity de- progress. fines a probability distribution for the duration of the activity. These distributions Effective program control depends on some are then combined to determine the pro- form of integrated cost, schedule, and tech- gram-level schedule estimate. This ap- nical performance management, such as proach enables PMs to estimate early in a the earned value management system program if there is a significant likelihood (EVMS). Effective scheduling is key to the of overrunning the program schedule and success of this technique. EVMS criteria do by how much. It also identifies program not dictate the use of specific scheduling activities that are on the “highest risk path.” techniques. However, they do seek formality, consistency, and discipline This technique can be used in any acqui- throughout the scheduling process. sition phase beginning with the completion of the first statement of work. The A five-step process for schedule prepara- schedule probability distribution function tion that is commonly used in program/ for each key activity should be developed project management includes: as soon as the activity is included in the master schedule. The distribution func- • Activity definition, tions should be periodically reviewed and revised, if necessary, at least once per phase. • Activity sequencing,

The technique should be applied by a small • Activity duration estimation, government-industry team consisting of schedule analysts and technical experts • Schedule development, and who understand the significance of previous risk performance assessments. See the • Schedule control. DSMC Risk Management Guidebook5 or the Defense Acquisition Deskbook, Section 2.5.2.46 Risk is inherent in all programs, and sched- for more details on the application of this uling is one element of risk. Uncertainty technique. introduced in estimating the duration of each activity causes most schedule risk. 3.6 SUMMARY PMs must assess the likelihood of failing to meet schedule plans and the impact of Scheduling is critical to the successful exe- that failure. Probabilistic techniques have cution of the planning and controlling proven to be very useful in conducting functions of program management. In the these assessments. planning phase, it contributes to the development of detailed functional plans 17 PROGRAM STRUCTURE/SCHEDULE (EXAMPLE) FY01 FY02 FY03 FY04 FY05 FY06 FY07 FY08 FY09 FY10 FY11 FY12 FY13 FY14 C&TD CE CAD System Devel & Demo Sys Int Sys Demo Full-Rate A Dec LRIP Prod & Deployment Operations & Support Rev Milestone B IPR Reviews C FRP IOC Block II & Phases Prototype B C FRP IOC Competition Block III

B C FRP IOC Contract Award C&TD SI SD LRIP PRODBlk II Blk II Blk III Blk III SD PROD SD PROD Technical

Reviews ASR SRR SFR PDR CDR FCA/ PCA CDR PCA CDR PCA SVR Developmental

& Operational DT&E LFT&E Testing EOA OT IOT&E FOT&E Deliveries (eng dev models) EDM LRIP Production RDT&E Procurement O&M MILCON Total Figure 3-3. Program Schedule/Structure (Example)

ENDNOTES 1 Defense Systems Management College, Acquisition Strategy Guide, Fort Belvoir, VA, January 1998. 2 Defense Systems Management College, Earned Value Management Textbook, Fort Belvoir, VA, April 16, 1998, 3 Ibid. 4 Program Management Institute, A Guide to the Program Management Body of Knowledge, Newtown Square, PA, 1996. 5 Defense Systems Management College, Risk Management Guidebook, Fort Belvoir, VA, May 1999. 6 Information on schedule risk techniques is in the Risk Assessment Techniques of the Front Line Wisdom & Advice portion of Section 2.5.2.4, Defense Acquisition Deskbook.

18 4 SCHEDULE TYPES AND THEIR EVOLUTION

4.1 INTRODUCTION • Events or milestones, that take place at a point in time, such as a Defense Acquisi- Previous chapters of this guide stress the tion Board (DAB) milestone review. point that scheduling is an intrinsic, indispensable part of program management and Dependencies or constraints among activi- a key output of the planning function of ties or events.1 that process. They also describe the relationship between the program Work Break- Currently, four types of schedules are in down Structure and scheduling, and intro- common use and depict the categories of duce the concepts of the Integrated Master information described above. They are the Plan and the Integrated Master Schedule. Gantt or bar chart, the milestone schedule/ Properly prepared and accurate schedules chart, the network schedule, and the pro- are invaluable tools in the overall manage- duction schedule. The evolution, character- ment of programs. They provide a road istics, and uses of each of these schedules map of where the project is going, the are described in the following paragraphs, resources required to accomplish the vari- and a more detailed treatment of each of ous project tasks, a means to determine them is contained in subsequent chapters. progress, and an effective way to present status information. This chapter contains 4.2.1 Gantt and Milestone Charts information on the various types of schedules generally in use today, their character- Gantt charts and milestone charts are nor- istics, advantages and disadvantages, and mally combined to show a program’s how they have evolved. Subsequent chap- schedule; therefore, they are discussed in ters provide more detailed information on this context. The Gantt chart is used to each of the schedule types, along with in- provide information concerning activities. formation on the selection and use of It is commonly referred to as a bar chart, scheduling software. since it depicts an activity as a horizontal bar imposed over a time-line, or calendar. 4.2 SCHEDULE TYPES It shows the planned start and finish dates for the activity and may provide informa- Schedules can be presented in a variety of tion about task progress, including sched- ways. Regardless of how they are dis- ule slips or gains. Figure 4-1 is an example played, schedules essentially convey in- of a simple Gantt chart that shows the formation concerning one (or a combina- planned schedule for four activities. tion) of the following categories: Progress in accomplishing each activity can be shown on each of the bars, as shown • Activities or tasks to be accomplished by the shaded portions of activities 1 and 2. over a period of time, and 19 The Gantt chart was the first formal sched- improving its utility. The Gantt chart is uling technique developed. It dates back very useful in reporting project status and to the early 20th century when Henry L. in managing individual activities or simple Gantt first introduced it while working at projects with few tasks. the Frankford Arsenal during World War I. It was developed to provide a more Subsequent to the development of the Gantt formal and systematic way to schedule chart, planners and managers used a simi- tasks when time was an imprtant factor. lar approach to depict information about significant project events, focusing on spe- The Gantt chart has survived in its basic cific points in time. These events repre- form to this day and continues to be sented project milestones—hence the in- widely used as a scheduling tool at all troduction of the milestone chart. The mile- levels within organizations. Its value stone chart shows when an event is sched- lies in its simplicity and its ability to uled and when it is actually accomplished. convey considerable information in a Figure 4-2 is an example of a milestone clear and concise manner. In the past, the chart showing the status of four events; principal shortcoming of the traditional each of these events represents the comple- Gantt chart was its inability to clearly tion of the four activities shown in the depict dependencies or constraints example Gantt chart in Figure 4-1. among activities, making it difficult to analyze schedules and optimize the allo- Like the Gantt chart, the strength of this cation of resources to the activities. Some milestone chart as a scheduling technique scheduling software programs now make lies in its relative simplicity and its ability it possible to show relationships, thereby to concisely display project information,

Activity Jan Feb Mar Apr May Jun

Identify User Requirements

Identify Performance Requirements

Identify Interface Requirements

Prepare SW Requirements Spec

Legend

Planned Actual Now Figure 4-1. Gantt Chart Example

20 Event Jan Feb Mar Apr May Jun

User Requirements Identified

Performance Requirements Identified

Interface Specs Identified

SW Requirements Spec Completed

Legend

Planned Actual

Figure 4-2. Milestone Chart Example especially at the “big picture” level. How- Perhaps the biggest shortfall of the Gantt ever, it does have shortcomings that limit and milestone charts is that neither of its effectiveness in day-to-day project man- them, nor the combination of both, allow agement. As shown in Figure 4-2, the mile- detailed schedule analysis. However, stone chart can depict the events corre- every PM must know and understand sponding to the completion of an activity. Gantt and milestone charts for two simple reasons: everybody uses them, and nor- However, it does not reflect the progress in mally, one of the first steps in the planning accomplishing the activity. In this case, a process is to construct a schedule using a manager relying on this milestone chart Gantt chart. information could be surprised if the planned completion date is not achieved. 4.2.2 Network Schedules With no warning or indicators of schedule slippage, the manager loses any flexibility Network scheduling was developed to in attacking the underlying problems caus- overcome the primary shortcoming of the ing the slippage. This shortcoming can be Gantt and milestone charts—the inability compensated for by the addition of interme- to clearly portray the relationships, depen- diate events or through the use of combined dencies, and constraints among the project Gantt and milestone charts. This is discussed activities and events. A network schedule in more detail in the next chapter. is a graphical display of a project, includ- Another weakness of the milestone chart is ing a representation of these relationships. the difficulty to clearly visualize the Figure 4-3 shows an example of a network relationships, dependencies, and con- schedule for a simple project. straints among the various project/program activities and events. In spite of these In this example, the lines represent project shortcomings, the milestone chart can be activities A through H; the nodes repre- an effective way of presenting the project sent the events associated with the begin- or program status at higher levels of man- ning and end of the activities. The net- agement review. work shows the following constraints 21 B E

A C GH

D F

Figure 4-3. Network Schedule Example among the activities: activity A must be was being applied to large, complex pro- completed before activities B, C, or D can grams. The first major network schedul- begin; B must be completed before E can ing technique developed was the Pro- begin; F cannot begin until D is completed; gram Evaluation and Review Technique, G cannot begin until C and E are done, and or PERT, which was used as a manage- H cannot begin until F and G are comment tool for scheduling and controlling pleted. In addition to showing this type of the Navy’s Polaris missile program. PERT sequencing constraints, network schedules enables managers to visualize the entire can also show the time and resources program, see interrelationships and de- planned for each activity and thus provide pendencies, and recognize when and managers with a mechanism to monitor where delays are acceptable. One of the and control the project. A later chapter key features of PERT is the use of prob- covers network schedules in detail. ability techniques to develop a set of time estimates for each program activity, The advent of network schedules can be making it particularly well-suited for pro- traced back to the 1920s and the evolu- grams where it is difficult to make accu- tion of operations research. Analysts re- rate estimates with high confidence. Con- alized the inability to depict dependen- current with the development of PERT, cies and constraints was a major short- the construction industry developed a coming of existing scheduling techniques, network scheduling system based on the and attempted to solve the problem concept of critical path. A project’s criti- through the application of network theory. cal path is the most time-consuming route The translation of this theory into a usable through the network activities that must scheduling tool was hindered by the in- be completed in order to finish the project. ability to process network-related data This approach, named Critical Path Method in a timely fashion. The development of (CPM), was designed to focus on perfor- the computer provided the means to au- mance time and total program cost. Some tomate this data processing and, by the publications refer to CPM as the Arrow 1950s, the concept of network scheduling Diagram Method (ADM). 22 PERT and CPM scheduling techniques have In spite of the strengths of network schedul- many similarities. For example, each shows ing techniques, there are some limitations. the relationships among activities and The value of network schedules is directly events, both include the project’s critical dependent on the validity of the time esti- path, and the structure of each allows analy- mates for each activity. In addition, it is sis of the tasks to be done, resources as- sometimes difficult to accurately portray signed to do them, and the time associated all activities and relationships, especially with each task. Both techniques use nodes for very large, complex programs. Thus, to represent events (beginning and end of considerable “up front” work is required activities) and lines to represent the activi- to develop an effective network schedule. ties. Detailed networks, once developed, tend to be the focus of management attention A third network scheduling technique is the when, in fact, there will undoubtedly be Precedence Diagram Method (PDM), which other factors not on the display that will was developed subsequent to the PERT/ require management attention. CPM techniques. Its function is to permit a more accurate depiction of relationships 4.2.3 Production Schedules among various activities than is possible using the other two techniques. PERT/ Production scheduling involves the plan- CPM techniques are essentially limited to ning, execution, and control of repetitive “finish-start” relationships (i.e., activity B activities, such as the manufacture of a cannot start until activity A is completed). large number of identical items. Efficient The PDM technique can depict other rela- production requires the proper balance of tionships that permit a more accurate and materials, facilities, and personnel skills. realistic portrayal of the program’s activi- It also requires a means to monitor the ties, such as “start-start” (i.e., activity B can- production process. not start until activity A starts). The technique accomplishes this through the use of The Line of Balance (LOB) technique, while nodes to depict activities and lines to depict not truly a scheduling tool, is such a moni- relationships. These three techniques are toring technique that can provide early discussed in greater detail in Chapter 6. warning of potential problems that can Network scheduling techniques provide affect program schedule. It is especially managers with a powerful tool for schedul- useful for monitoring repetitive processes ing and controlling their programs/projects. where it is essential to balance inventory In general, they permit the graphic por- acquisition with the production process trayal of project activities and relationships and delivery requirements. The LOB tech- among the activities. This provides the nique consists of four elements: (1) objec- basis for determining the project’s critical tives of the program, i.e., contract sched- path, predicting shortages, and identifying ule and actual deliveries; (2) production possible reallocation of resources to solve plan; (3) current program status or inven- problems. Through the use of readily avail- tory; and (4) a comparison between where able software, network schedules are fairly the program is and where it’s supposed to easy to update and rework, thus providing be, (that is, program inventories versus managers with current program/project sta- the LOB). These elements are discussed tus information and control over activities in more detail in Chapter 7. and schedules.

23 The origin of LOB is not clear, but it is the method that allows them to meet their believed it was developed to help manage goals. The choice of schedule type depends defense-related contracts in the 1940s and on a number of factors, such as, the purpose 50s. It is still used today in both defense and of the schedule, its intended use, and the commercial industry. While government decisions to be made from the information PMs or their staffs will probably not need to presented. For example, day-to-day man- directly develop or apply the LOB tech- agement of a project consisting of a number nique, they should understand it and real- of related and complex activities may re- ize that it can be a valuable tool for contrac- quire a schedule that depicts the tasks, their tors to monitor the status of production planned duration, dependencies, progress, contracts and to present status information. and resources allocated to each of them. If a PM must do detailed schedule analysis of This technique can point out problems be- this type of project, then the PM will most fore their impact on finished product deliv- likely use a network schedule. This method eries shows up, thereby allowing managers is the only way to use probability distribu- to make corrections. It also allows manag- tions for time estimates rather than complet- ers to see, in the middle of a contract, whether ing an activity and project in a certain time. they can meet the contract schedule if they continue working as they have been. An- On the other hand, the management of a other advantage of LOB is that it focuses single activity may require a schedule that attention on the production activities where reflects only the time planned for accom- there are problems, thereby facilitating ini- plishing the task and the current status. tiation of corrective action. Schedules showing only events, such as the completion dates of planned activities, or There are some limitations with the LOB bar charts may be sufficient in those cases technique. First, it is best suited for produc- when the audience may not be concerned tion and/or assembly-type processes that with the details of the activities. are stable. The activities that make up the production plan must be definable and well As a rule of thumb, Gantt and milestone understood. Second, while this technique charts are useful to present information and pinpoints where a problem exists, it cannot summarize program activities. They are identify the specific problem. also usually the starting points for detailed planning and creating a network schedule. 4.3 SUMMARY Network schedules are usually created for detailed planning and analyses. They are Each scheduling method has strengths and necessary to determine the feasibility of limitations. Program Mangers must be fa- meeting program goals, assessing risk, and miliar with all of the techniques and choose conducting sensitivity analyses.

ENDNOTES 1 Quentin W. Fleming, John W. Bronn, and Gary C. Humphries, Project and Production Scheduling, Chicago, IL, Probus Publishing Co., 1987, p. 45.

24 5 GANTT AND MILESTONE CHARTS

5.1 DESCRIPTION There is no standard set of Gantt chart symbols. Planners should define them and con- As discussed in Chapter 4, the Gantt chart sistently use them throughout the chart. Fig- is one of the oldest planning tools in ure 5-1 shows an example of the symbols that existence and is still used today at all could be used in Gantt charts. levels of project management. For example, PMs use Gantt charts to report The schedule is displayed as a series of information concerning program activi- horizontal bars representing the duration of ties at milestone decision briefs, while activities. A manager may show actual engineers may use them to manage the progress against the schedule by shading in tasks associated with design activities. each bar as activity progresses or may use a Because PMs often use Gantt and mile- colored bar that is parallel to the schedule stone charts to report information to re- bar. Figure 5-2 shows a simple Gantt chart view groups, they are treated jointly in that illustrates activities involved in devel- this chapter. oping components of a weapons system. This type of display can be useful for convey- In its simplest form, a Gantt chart is a ing information about the program to those schedule that shows the start/stop dates involved in its review or those charged with of a program’s individual activities. It its day-to-day management. uses symbols superimposed on a calendar to provide information about the From this example, we can see that as of late original plan, the status of the activity, March, the design, fabrication, and assembly and any forecasted changes to the plan. of the payload are ahead of schedule, [A].

Symbol Meaning

Planned activity schedule

Status of activity

Forecasted completion behind schedule

Forecasted completion ahead of schedule

Figure 5-1. Example Gantt Chart Symbols

25 Activity JFMAMJJASOND

Payload Design [A]

[A] [B] Payload Fabrication

[A] [C] Payload Assembly

Test & Rework

Guidance & Control Design

Guidance & Control [D] [E] Fabrication

Guidance & Control [E] Assembly

Guidance & Control Test & Rework

System Integration

System Test & Rework

Now Figure 5-2. Example Gantt Chart

Based on this information, and an analysis guidance and control subsystem is not go- of the activities, the PM has revised the ing as well as planned. As of late-March, planned completion date for the payload the fabrication is well behind schedule, fabrication, [B]. In analyzing the current [D]. After reviewing the progress and re- status, the PM has determined that much of maining work, the PM has slipped the the work in payload assembly will have to planned completion dates for the fabrica- be done toward the end of the planned tion and assembly activities, [E]. They be- activity period. (In other words, the work is lieve that it is too early to revise the planned not uniformly distributed throughout the completion dates for test and rework, and period.) Thus, even though this activity is the system integration and test activities. ahead of schedule now, the PM has de- However, the slippage already experienced cided not to revise the planned completion should serve as a warning that this entire date for assembly and test, [C]. This Gantt development effort may be in trouble and chart also shows that development of the will require close monitoring. 26 While the Gantt chart focuses on activities The important thing is that the symbols be and their duration, the milestone chart fo- clearly defined and consistently applied. cuses on planned significant events scheduled to occur at specific times in the pro- Figure 5-4 shows an example milestone gram. Such events could be the initiation chart for the program described in the Gantt or completion of a particularly important chart in Figure 5-2. Note that events dis- or critical activity, equipment deliveries, played correspond to the beginning of reviews, or approval dates. Like the Gantt some activities and the completion of all of chart, the milestone chart uses symbols them. Other events displayed represent imposed on a calendar to provide informa- important occurrences and key decision tion about planned and actual completion points within each of the activities, e.g., dates and any revisions to the milestone preliminary and critical design reviews, schedule. There is no standard set of sym- “make or buy” decision, etc. In this ex- bols for milestone charts. Figure 5-3 shows ample, we see that as of late-March pay- the symbols prescribed for reporting mile- load design has progressed on schedule, stone information within the Air Force [A], and that planned completion date for Material Command. Different scheduling fabrication has been revised ahead of the software will often use unique symbols. original schedule, [B]. As discussed in the

Standard symbols have been adapted for Air Force milestone schedules. The most common symbols used and their meanings are shown below. Basic Symbol Meaning

Schedule Completion

Actual Completion

Previous Scheduled Completion—Still in Future

Previous Scheduled Completion—Date Passed

Representative Uses Meaning

Anticipated Slip—Rescheduled Completion

Actual Slip—Rescheduled Completion

Actual Slip—Actual Completion

Actual Completion Ahead of Schedule

Time Span Action

Continuous Action

Figure 5-3. Example Milestone Chart Symbols

27 JFMAMJJASOND

Payload Design Begin Payload Design [A] Payload Preliminary Design Review (PDR) Payload Critical Design Review (CDR) Complete Payload Design

Payload Fabrication Make or Buy Decision [B] Tooling Complete Fabrication Complete

Assemble Payload Begin Assembly Delivery of Parts Complete Assembly Complete

Payload Test & Rework Test Plan Complete Test Readiness Review Test & Rework Complete

Guidance & Control Design Begin G&C Design G&C PDR G&C CDR Complete G&C Design

Fabricate G&C Make or Buy Decision [C] Tooling Complete [D] Fabrication Complete

Assemble G&C [D] Begin Assembly Delivery of Parts Complete [D] Assembly Complete

Test and Rework Test Plan Complete Test Readiness Review Test & Rework Complete

Integrate Payload and G&C Begin Integration Complete Integration

Test & Rework Test Plan Complete Test Readiness Review Test & Rework Complete Now Figure 5-4. Example Milestone Chart

28 JFMAMJJASOND

Payload Design

Payload Preliminary Design Review (PDR) Payload Critical Design Review (CDR) Complete Payload Design

Payload Fabrication

Make or Buy Decision Tooling Complete Fabrication Complete

Assemble Payload

Delivery of Parts Complete Assembly Complete

Payload Test & Rework

Test Plan Complete Test Readiness Review Test & Rework Complete

Guidance & Control Design

G&C PDR G&C CDR Complete G&C Design

Fabricate G&C

Make or Buy Decision Tooling Complete Fabrication Complete

Assemble G&C

Delivery of Parts Complete Assembly Complete

Test and Rework

Test Plan Complete Test Readiness Review Test & Rework Complete

System Integration Payload and G&C

Complete Integration

System Test & Rework

Test Plan Complete Test Readiness Review Test & Rework Complete

Figure 5-5. Example Combination Chart

29 Jun ‘99 Jul ‘99

Activity Name Assign- Cost/ ment 7 14 21 28 5 12 19 26 Budget Cost Budget

Requirements Planning

Re view existing Mary $10,000 $10,000 100% systems

Perform work flo w James $10,000 $9,000 90% analysis

Model process Mary, $12,000 $12,000 100% James

Identify u se r Peter $15,000 $17,000 113% require ments 30 Identify Chris $11,000 $9,500 86% performance requirement

Identify interface James, $15,000 $0 0% require ments Peter

Prepare SW All $12,000 $0 0% Require ments Spec

Software All 0% Require ments Review

Figure 5-6. Gantt Chart with Amplifying Information As discussed in the Gantt chart example, activity, is a standard feature of the par- there are problems in the fabrication of the ticular program used to create this Gantt guidance and control subsystem. One of chart.1 The Assignment, Cost, and Cost/Bud- the events selected as a milestone was the get ratio columns are not standard features completion of the tooling necessary for but were added to the database to demon- fabrication. From the example, we see that strate how the charts may be customized to this event experienced an actual slip of meet individual needs. Note that the user approximately one month, [C]; this, in turn, may create computation fields, such as the has caused the Program Manager to revise percentage and totals fields shown in the the scheduled completion dates for fabri- figure. cation, parts delivery, and assembly, [D]. 5.2 CONSTRUCTING GANTT AND Managers rarely use pure Gantt or mile- MILESTONE CHARTS stone charts. Normally they integrate the information from these charts and display Gantt and milestone charts are relatively it in a combination chart. Such a chart can easy to construct when compared to the be useful in displaying the planned and complexity of network charts. The first actual duration of activities using the Gantt step is to decide the level at which the chart symbols and in monitoring the project is to be planned, tracked, and re- progress for completing key events in these ported. This decision should consider such activities using the milestone symbols. Fig- things as the needs of the entire project ure 5-5 is a combination chart showing the team, and the degree of risk associated activities and events described in Figures with the various program activities. Most 5-2 and 5-4. likely there will be a need to manage and track at a low level and report at a higher Whereas the simple Gantt, milestone, or level. Current scheduling software has the combination charts may be suitable for capability to handle activities at various reporting program status, most managers program levels allowing insight and man- need additional information to plan, moni- agement at the lower levels and permitting tor, and control activities. New software roll up of information at higher levels for applications increase the utility of these reporting purposes. To accomplish this, charts by making it easy to add informa- charts must be developed in a logical and tion, such as budget, cost, resources, etc. consistent manner.

Today’s programs use databases to store The next step in constructing the charts is related schedule information and then al- the identification of activities and mile- low users to filter, sort, and display infor- stones to be displayed, tracked, and moni- mation in a variety of ways. They also tored. The WBS should be used as the allow users to tailor the software to their primary source for this identification. If a needs by adding customized information WBS is not available, or if it does not go to the database. Figure 5-6 shows how to down to the necessary level, additional display the relationship of one activity with planning must be done to clearly define another by drawing lines between related and identify activities to be managed, activities. The Budget column, in which the tracked, and reported. Other sources for manager enters the budgeted cost for the identifying activities and events include 31 the Acquisition Strategy, the Acquisition 5.3.2 Disadvantages Program Baseline, the Risk Management Plan, and the Integrated Management Plan, (1) Difficult to use for detailed sched- and the Integrated Management Plan. ule analysis

5.3 GANTT AND MILESTONE (2) Do not show the effects of late or CHART ADVANTAGES AND early activity starts DISADVANTAGES

Gantt and milestone (or combination) charts (3) Do not represent dependencies provide a simple, effective means to among activities as well as other schedul- present project information, and a way to ing methods monitor and control smaller projects. Us- (4) Do not reflect the uncertainty in the ing these charts as scheduling tools has planned activity duration or event date many advantages, but also limitations that should be understood. These pros and (5) Only as reliable as the estimates on cons are presented below. Evolving sched- which they are based; looking at the chart uling software includes features that over- doesn’t indicate which estimates are the come some of the shortcomings to varying most reliable degrees. (6) Do not allow quick or easy explora- 5.3.1 Advantages tion of the consequences of alternative actions. (1) Simple to prepare and update, 5.4 HOW AND WHEN GANTT AND (2) Information portrayed in easily un- MILESTONE CHARTS ARE derstood format, EMPLOYED

(3) Relatively inexpensive to prepare Gantt and milestone charts are best used using software tools, for displaying the planned activities and events of a project and the progress in (4) Relate activities and calendar dates, meeting them. This makes them very useful for presenting schedule and program (5) Easy to roll up information into status information in a concise simple for- summary form, mat at such things as programor activity reviews. (6) Useful first step for preparation of more complex type schedules Because of its simplicity and ease of inter- pretation, it is a particularly good tool for (7) Reliable estimates can be developed communicating to higher management when the work is repetitive and when the when information must be presented product is easy to measure quantitatively. quickly and efficiently. These charts may

32 also be sufficient for management and con- 5.5 SUMMARY trol of simple projects. However, they have limited utility for managing more As scheduling tools, Gantt and milestone complex projects, since they do not easily charts provide a simple and effective means capture interrelationships among activi- for displaying actual versus planned ties and events or reflect the uncertainty progress of a program and for showing associated with time and resource esti- schedule changes that have occurred. The mates. Generally, they do not provide the major drawback of Gannt and milestone level of information necessary for the effec- charts is the limited degree fo detail and tive monitoring and control of such projects. dependency information they can portray. However, recently developed software scheduling applications now make it possible to show more of the relationships among project activities and events.

33 ENDNOTES 1 This figure is an adaptation of sample charts from Fast Track Schedule sample charts.

34 6 NETWORK SCHEDULING

6.1 DESCRIPTION ing the overall scheduled completion date for the program? Driven by the increase in project complexity, managers developed the need for better • Among program tasks, where should schedule and control methods than those management efforts be concentrated at provided by Gantt and milestone charts. any particular time? The shortcomings of these charts gave rise to network scheduling. Over time, different Networks are a graphical portrayal of the applications of network theory were devel- activities and events of a project. They show oped to address the needs of managers. how each activity relates to others in the Today, essentially three networking tech- project, the sequence of activities, and the niques are in use: the Program Evaluation need to perform some tasks before others. and Review Technique (PERT); the Critical Figure 4-3 is an example of an ADM network Path Method (CPM) [these two techniques schedule. Networks also facilitate the deter- are also known as Arrow Diagram Methods mination of the impact of early or late starts (ADM)] and the Precedence Diagram or finishes, provide information about the Method (PDM). Each is discussed later in allocation of resources, and allow managers this chapter. to do “what if” analyses. With this information, managers may view the status of the All of these techniques provide the manager plan, analyze progress, and evaluate alter- with powerful tools to plan, analyze, moni- natives. tor, and control the project and to manage the resources necessary to accomplish project To apply these networking techniques, the tasks. They can help the manager answer following conditions must exist: the following questions: • All program activities must be clearly • When is each activity or task of the defined, including identifiable start and program scheduled to begin and end? completion points.

• Which activities must be finished on • A logic diagram showing the sequence time to avoid missing the scheduled pro- and interrelationships of activities must be gram completion date? developed.

• Can resources be shifted to critical • The time to complete each activity parts of the program (those that must be must be estimated as accurately as pos- completed on time) from non-critical parts sible. (those that can be delayed) without affect-

35 Accomplishing these things may require estimated times could be compared against considerable effort and the involvement of actual completion times in a number of cases, people familiar with the overall project and the variation would look like the curve in those responsible for executing various Figure 6-1. groups of activities. This up-front effort provides an understanding of project re- The expected time, t is the weighted aver- quirements and early identification of po- age, or mean time, for an activity based on tential problem areas. the beta distribution and is determined from the following formula: 6.1.1 PERT a +4bm + t = In 1958, the U.S. Navy introduced the con- 6 cept of network scheduling techniques by developing PERT as a management control Using the expected times and other statisti- system for the development of the Polaris cal properties of the beta distribution for missile program. The focus of PERT was to each activity, it is possible to determine an give managers the means to plan and con- expected time for completion of the project trol processes and activities so the project and the likelihood (probability) that this ex- could be completed within the specified time pected completion time will be met. It is also period. The Polaris program involved 250 possible to determine the critical path for the prime contractors, more than 9,000 subcon- project—the most time-consuming path tractors, and hundreds of thousands of tasks. through the network activities and events to project completion. Any delay on this path PERT was introduced as an event-oriented, will delay the completion of the project. probabilistic technique to increase a PM’s control in projects where time was the criti- PERT is most useful when it is difficult to cal factor and time estimates were difficult either accurately estimate the time required to make with confidence. The events used in for project activities or to determine the per- this technique represent the start and finish centage of work accomplished within an of the activities. PERT uses three time esti- activity. The percentage of work accom- mates for each activity: optimistic, pessi- plished can be especially important when mistic, and most likely. From these esti- analyzing the adequacy of resources applied mates, an expected time is calculated based to an activity. Projects best suited for PERT on a beta probability distribution for each are one-of-a-kind complex programs that activity. The developers of PERT chose the involve new technology or processes and beta probability distribution because it could research and development. accommodate nonsymmetrical situations. They assumed that the probability of an Fllowing the success of the Polaris program, estimate being too optimistic would not be PERT became widely used throughout the equal to the probability that the same esti- systems acquisition community, to include mate would be too pessimistic. That is, if attempts to combine it with cost data or

36 Probability of Meeting Schedule

am b Most Most Most Optimistic Likely Pessimistic Time Time Time

Figure 6-1. Beta Distribution with PERT Time Estimates other non-scheduling aspects of program the manager is better able to assess problems management. As a result, PERT became so as the program evolves. cumbersome that the cost of maintaining it far outweighed the benefit. Consequently, 6.1.2 CPM the use of PERT declined and, by the 1970s, it was only occasionally employed in de- The CPM scheduling technique was intro- fense system programs. Over the last few duced at approximately the same time as years, it has again become relatively popu- PERT. It was developed by J. E. Kelly of lar, particularly in the private sector. This Remington-Rand and M. R. Walker of resurgence is due, in part, to the develop- DuPont to aid in scheduling maintenance ment of PERT software or other networking shutdowns in chemical processing plants. software programs that can be run on micro- Over the years, CPM has enjoyed more use computers. than any other network scheduling technique. It is based on the concept of critical In spite of misuses that have occurred in path and was designed to focus on the time PERT applications, the technique can be a and resources, particularly cost, necessary very useful tool because it enables the man- to complete the activities of a project. ager to visualize the entire program, see interrelationships and dependencies, and Although CPM and PERT are conceptually recognize when delays are acceptable. Thus, similar, some significant differences exist,

37 most as a result of the type of projects best completed, the following procedures are suited for each technique. As discussed applied: earlier, PERT is better to use when there is much uncertainty and when control over • Complete and annotate the cumula- time outweighs control over costs. PERT tive time required to reach each node along handles uncertainty of the time required to the paths—This will indicate the earliest complete an activity by developing three time work can start on the next activity. The estimates and then computing an expected final number will indicate total time required time using the beta distribution. CPM is to complete a particular path. better suited for well-defined projects and activities with little uncertainty, where ac- • Identify the critical path—This is the curate time and resource estimates can be sequence of events, or route, taking the long- made, and the percentage of completion of est time to complete. an activity can be determined. In CPM, because of the greater certainty, a single • Starting at the program completion time estimate is used. This estimate is the node on the right side of the diagram, begin time planned for the activity under normal working backward and compute the latest conditions; it approximates the most likely time an activity can start without delaying time estimate in PERT. The normal cost the overall program—For example, if the estimate is the cost associated with finishing total program takes 40 weeks and the final the program in the normal time. A second activity requires 5 weeks, this activity can- time and cost estimate, the crash estimate, is not begin later than week 35. For CPM, the also used in the CPM technique. The crash difference between the latest and earliest time estimate is the time that will be re- start of an activity is the slack or float. The quired to finish an activity if a special effort critical path contains no slack or float time. is made to reduce program time; crash cost For PERT, the difference between the earli- is the cost associated with performing the est event time and the latest event time at effort on a crash basis so as to reduce the time each event is the slack/float time. to completion. This is discussed in more detail with a later example. The use of these procedures is illustrated in a later example. CPM is activity-oriented, concentrating on activity start (early start, late start) and fin- 6.1.3 PDM ish times (early finish, late finish); whereas PERT is event-oriented, concentrating on PDM is an activity-oriented technique that early event time and late event time. The was developed subsequent to PERT and network diagrams used for CPM and PERT CPM. The impetus behind this develop- are essentially the same (see Figure 4-3), as ment was the need for greater flexibility in are the procedures for using them. As dis- dealing with relationships and constraints cussed earlier, certain actions are essential to between project activities. applying network scheduling techniques. The activities/events composing the project, PERT/CPM, or the arrow diagram method the relationships among them, and their time (ADM), essentially treats all relationships as estimates must be identified, and a network “finish-to-start” constraints; that is, Activity diagram developed. Once the diagram is A must be completed before Activity B can 38 begin. There are ways within PERT/CPM to such lags are the time required for the move- circumvent this limitation, but they are cum- ment of parts or components from one activ- bersome and add more complexity to the ity site to another, or the time involved in technique. the reallocation of resources—people, equipment, and facilities. Figure 6-3 shows ex- The PDM technique provides the capability amples of constraint lags and how they can to treat other types of relationships that oc- be depicted. These lags could be repre- cur in complex projects. Figure 6-2 shows sented as activities in the ADM technique, examples of these types of relationships or but this could add needless complexity to constraints. the schedule. The use of lags in the PDM technique is much less complicated. In addition to depicting different relationships between activities, PDM also PDM uses the same underlying principles as handles time lags that would normally oc- the other networking techniques: clearly cur as the project progresses. Examples of defined activities, accurate time estimates,

Symbols Constraint

Finish-to-Start A B B cannot start until A is finished— normal PERT/CPM constraint

A Finish-to-Finish B cannot finish until A is finished

A Start-to-Start B cannot start until A starts B

A Start-to-Finish B cannot finish until A is started (Rarely used)

A Percent Complete 70% Remaining 40% of B cannot be 40% started until 70% of A is completed

Figure 6-2. Example PDM Relationships/Constraints 39 critical path, etc. The difference between lines. In PDM, the nodes represent the PERT/CPM (ADM) and PDM is in the way estimates, early and late start and finish the network is portrayed. In PERT/CPM, dates, and other appropriate information the network nodes represent the events as- are normally shown in the boxes. Figure 6- sociated with activities (i.e., the beginning 4 is an example of an activity node. The lines and end of activities), and the connecting connecting the nodes represent the relation- lines represent the activities and the rela- ships between the activities, e.g., finish-to- tionship/constraints. Activity time and re- start, start-to-start, etc. The use of PDM is source estimates are normally shown on the demonstrated in a later example.

Symbols Constraint

Lag + 5 days Finish-to-Start with Lag A B B cannot start until 5 days after A is completed

A Start-to-Start with Lag B cannot start until 7 days after A has started Lag + 7 days B

Finish-to-Start with Negative Lag Lag - 5 days A B B cannot start until 5 days before A is completed

Figure 6-3. Example PDM Constraints with Lag Time

Early Start Time Early Finish Time 7/12/99 7/15/99

Duration 3 Days

Activity Identification Information

Resource Requirements

Late Start Time Late Finish Time 7/14/99 7/17/99

Figure 6-4. Example PDM Activity Node

40 6.2 NETWORK SCHEDULING • Show resources associated with ac- ADVANTAGES AND tivities and time. DISADVANTAGES 6.2.2 DISADVANTAGES Network scheduling techniques provide the mechanisms necessary to conduct a system- • Network construction can be diffi- atic, disciplined, and thorough review of cult and time consuming. what will be required to conduct and complete a project. Such an approach is essential • Only as sound as the activity time for large, complex projects and is also useful and resource estimates. in managing smaller, less complicated projects. The advantages and disadvantages • Sometimes difficult to portray of these techniques are identified below. graphically—too many lines, nodes and intersections. 6.2.1 ADVANTAGES • Not particularly good for conveying • Provide graphical portrayal of pro- information in briefings/reviews. ject activities and relationships/constraints • Complex networks, once sketched out on a large wall chart, tend to become the • Force communications among team focus of management attention when, in members in identifying activities fact, a manager should be paying attention to factors not on the chart, such as manage- • Organize what would otherwise be ment/labor relations. confusing material, making it easier for managers to make tradeoffs and develop alter- 6.3 HOW AND WHEN NETWORK native plans SCHEDULES ARE EMPLOYED

• Provide capabilities to evaluate Network scheduling techniques can be very progress and control project useful in complex projects that involve new technologies or processes and that are not • Allow managers to predict shortages repetitive, such as production. They are not and act on them early particularly easy to use for presentations because of their complexity; however, they • Once prepared, permit easy update can be used as the basis for other scheduling and rework techniques that are more suitable for presentation of information, i.e., Gantt or mile- • Give managers more control over stone charts. activities/events and schedules Government managers may not use net- • Facilitate “what if” exercises work techniques in the day-to-day management of their programs. However, they • Provide the basis for Gantt and should have an understanding of the tech- milestone chart information niques to ensure that contractors are using them when appropriate. 41 The different types of network scheduling Path A-B-E-H=2+3+2+4=11 weeks techniques have many similarities. How- ever, each of them provides different types Path A-C-F-H=2+4+3+4=13 weeks of information that can be useful to managers in evaluating progress, developing Path A-D-G-H=2+8+9+4=23 weeks alternatives, and managing the allocation of resources within their projects. The follow- Thus, path A-D-G-H is the critical path ing examples show the types of information since it requires the greatest time. Any resulting from each technique and how man- delay along this path will cause a delay in agers may use them. project completion. The other paths are shorter completion. The other paths are 6.3.1 PERT EXAMPLE shorter than the critical path and, therefore, contain activities that can be completed be- Figure 6-5 shows a PERT network for a fore they are required. Therefore, delays project containing 8 activities (A-H), with along these paths may not result in delays in the nodes 1-7 representing the beginning project completion. In the above example, and end of the activities. The three time critical path activities, D and G, will require estimates discussed earlier in this chapter 17 weeks to complete. On path A-B-E-H, are shown for each activity. For example, for activities B and E will require 5 weeks to Activity A, the time estimates are optimistic complete. Thus, there will be 12 weeks of time=1 week, most likely time=2 weeks, and slack along that path. Actually, this slack is pessimistic time=3 weeks. The expected only along path B, E since A and H are on the time estimate for each activity, t, as derived critical path. Likewise path C-F has 10 weeks from the formula associated with Figure 6-1, of slack time. This concept of slack time, is also shown. From this information, the sometimes called float time or path slack/ project critical path can be computed by float, is important because it allows manag- adding the time estimates along all paths ers to reschedule activities not on the critical leading to project completion. In this ex- path to use resources efficiently. ample, the critical path is determined as follows:

3 (2, 3, 4) (1, 2, 3) t=3 B E t=2

A C F H 1 2 4 6 7 (1, 2, 3) (3, 4, 5) (2, 3, 4) (3, 4, 5) t=2 t=4 t=3 t=4 D G (7, 8, 9) (8, 9, 10) t=8 t=9 5

Figure 6-5. PERT Example 42 The following description of how slack time TE for node 3 is the value of TE from node 2

is computed is intended to illustrate the (TE=2) plus the duration of Activity B; for

concept that managers can use it to their node 3, TE=5. advantage. Fortunately, software programs compute slack time and managers do not To determine the latest starting times for have to make these calculations. each activity, begin at the completion of the project and work backward through the ac- Slack time should be computed for each tivities. Since Activity H is on the critical

activity in the network. One way of doing path, its value of TL=19. Activity E is not on

this is by comparing the earliest time an the critical path so its value of TL (shown on

activity can begin, TE, to the latest time the node 3) is the difference between TL at node

activity can begin, TL. The difference is the 6 and the time estimate for Activity E, TL=19- activity slack time. For all activities on the 2=17. The activity slack is the difference

critical path, TE and TL have the same value. between TE and TL at each node. For Activity

To determine the values of TE and TL for each E, the slack is TL-TE=17-5=12 weeks. This activity, start with the node representing the activity could start anytime between weeks beginning of the first activity and assign it a 5 and 17 without any adverse impact on the

value of TE=TL=0. Follow the critical path critical path. Activity B is not on the critical

and add the activity time estimate to the path so its value of TL is the difference be-

value of TE of the preceding node to get the tween TL at node 3 and the time estimate for

value of TE for the next node. For example, Activity B (17-3=14). This is not shown at the node at the completion of Activity A and node 2, since that node also represents the the beginning of Activity D has a value of start of Activity D, which is on the critical

TE=TL=2. Figure 6-6 shows how TE and TL path. The slack for Activity B is TL-TE=14- can be depicted on a network chart. Con- 2=12. (The same approach is used to deter- tinue along the critical path to node 7, which mine the slack for Activity C.) Slack is not

has a value of TE=TL=23, the time required to additive along a path; it must be shared by complete the project. Next, compute the all activities on the path. Thus, if Activity B values for TE for the remaining activities and starts at week 5 instead of week 2, Activity E nodes not on the critical path. The value of would have only 9 weeks of slack available.

TE=5 TL=17 3 (2, 3, 4) (1, 2, 3) t=3B E t=2 T =6 T =23 TE=0 TE=2 E TE=19 E T =0 T =2 T =16 T =19 T =23 L A L C L F L H L 1 2 4 6 7 (1, 2, 3) (3, 4, 5) (2, 3, 4) (3, 4, 5) t=2 t=4 t=3 t=4 D G (7, 8, 9) (8, 9, 10) t=8 t=9 5

TE=10 TL=10

Figure 6-6. PERT Example with Slack Time 43 Similarly, Activities C and F have a slack of time and crash estimates for each of the 10 weeks. activities.

The concept of slack and TE and TL can be The critical path for the CPM approach is very useful to managers, providing the basis determined in the same way as in the PERT for resource allocation and also providing example. While the concept of slack time the means to determine the probability of is essentially the same as in PERT, it is nor- meeting the project schedule. This latter mally calculated in a different manner using topic is beyond the intended scope of this four different values for each activity: guidebook; however, a number of available books provide detailed discussion of the • Earliest time the activity can start, ES application of PERT techniques. (See the bibliography in Appendix D.) • Earliest time the activity can finish, EF

6.3.2 CPM EXAMPLE • Latest time an activity can start, LS

As discussed earlier, PERT and CPM are • Latest time an activity can finish, LF. conceptually similar, in that both techniques use the same type of network structure, and To compute ES, start at the first activity and the concepts of critical path and slack time. move forward through the network paths. The following example will be used to illus- The earliest Activity A can start is at t=0. trate basic application of the CPM technique. The earliest that it can finish is ES plus the Figure 6-7 shows the same project as used in activity duration; thus for A, ES=0 and EF=2. the PERT example, with the single time esti- The earliest start for subsequent activities is mates for each activity. Table 6-1 shows the the EF of the preceding activity. For Activity

3 E( 2(17,19)5, 7) (2, 5) B 17) 3 (14, A (ES=0, EF=2) C (2, 6) F (6, 9) H (19, 23) 1 2 4 6 7 2 (LS=0, LF=2) 4 (12, 16) 3 (16, 19) 4 (19, 23)

D ( 19) 8( 2, 10 10, 19) 2, 10) ) ( , G 10 9( 5

Figure 6-7 CPM Examples

44 B, ES=2. The earliest finish time for each managers with information to effectively activity is the earliest start time plus the activ- manage their projects. Using percent of ity duration. For Activity B this is EF=2+3=5. work completed or that is remaining on When activities converge, such as E, F, and G ongoing activities, they can compare the at node 6, the earliest starting time for the next progress at a certain time with the original activity is the latest value of EF of the preced- plan. Based on this information, they can ing converging activities. develop revised time and cost estimates for these activities and forecast new start and To compute the latest times, make a back- completion dates for remaining activities ward pass through the network, beginning and a new project completion date. They with the last activity. The date to begin the can then use the new forecast dates to deter- pass can be either an established required mine action that can be taken and the appro- date or the early finish date for the project priate resource planning and reallocation, if completion. The latest starting date for the necessary. final activity is determined by subtracting the activity duration from the date used to begin The CPM technique provides managers with the pass. For subsequent activities, the latest the means to investigate ways and impacts finish date is the same as the latest starting of speeding up, or crashing, the schedule. date for the preceding activity. In the back- As part of the planning process, a set of crash ward pass, the value of LF for an activity that estimates should be developed if possible. precedes a set of diverging activities in the The estimates for this example are shown in network (activity A in the example) is the Table 6-1. earliest of the values of LS of the diverging activities (B, C, D). This table shows the time and cost estimates and the crash cost per week. To crash a The values of ES, EF, LS, and LF for all activi- schedule, some key points must be consid- ties are shown in Figure 6-7. With this infor- ered: mation, one can determine the slack for each activity. Slack is determined using the fol- • Crash only along the critical path. lowing formula: Slack=LF-EF=LS-ES. • When an activity is shortened, one or The relative certainty of time and resource more new critical paths may emerge. estimates enables managers to determine the percent of work completed in each activity as • Parallel critical paths increase risk the project progresses. Being able to estimate dramatically. the percent of completion provides managers with the means to redistribute resources if • Generally, least additional cost is the an activity is falling behind schedule. For criterion used to select which activity to example, if an activity has fallen behind sched- crash, but other considerations (e.g., per- ule, it is possible to estimate the work remain- sonnel hours) could be used. ing and the cost of applying additional resources to complete the activity on schedule. In this example, assume that the project must Network scheduling techniques, particularly be crashed by 4 weeks at the least additional CPM, used on projects with relatively cer- cost. Looking at the activities on the critical tain time and cost estimates can provide path, select the one with the lowest weekly 45 Table 6.1 "Crashing" the Network

Crash Time Estimates Per Cost ($) (Accelerated Min Activity Activity Critical Per add'l time reqd Crash Number (wks) Path Activity/wk cost/week) per Activity Priority

A 2 Yes $4,000 $6,000 2

B 3 No $2,000 $600 3

C 4 No $3,000 $400 2 1st D 8 Yes $5,000 $3,000 6 (-2 days x $3,000 per day) E 2 No $1,500 $700 2 =$6,000

F 3 No $2,500 $650 3

G 9 Yes $20,000 $5,000 7 2d (-2 days x $5,000 per day) H 4 Yes $8,500 $6,000 3 = $10,000

Note: Example same as Figure 6-7 crash cost; in this case it is Activity D, which (duration=2) will require 6 weeks to com- can be crashed from 8 to 6 weeks for an plete. However, Activity D can not be com- additional $6,000. Next, crash Activity G by pleted until Activity C is finished, which is 9 2 weeks at a cost of $10,000. Reducing both weeks (5 weeks for Activity A and 4 weeks of these activities does not change the criti- for C). The difference between the 9 and 6 cal path. weeks (i.e. 3 weeks) must be added to the time to complete Activity D when determin- 6.3.3 PDM EXAMPLE ing the critical path. This is shown below in the parenthetical term for Path B-D-G-I. The The PDM technique focuses on program critical path for this example is determined activities and the meaning of the constraints as follows: among activities. This technique is used in many scheduling software applications, and Path A – C – F – I = 5 + 4 + 5 + 3 = 17 weeks it relies on the same concepts—critical path, slack time, etc., as the other network sched- Path B–D–G–I = 4+(2+3)+2+3 = 14 weeks uling techniques. Path B–E–H–I = 4+5+2+3 = 14 weeks Figure 6-8 shows a PDM network for a project with Activities A–I. (Assume that the unit of Thus, Path A-C-F-I is the critical path. working time (duration) is one week.) Note that Activity B cannot start until Activity A The slack times for the activities are deter- starts, and Activity D cannot end until Ac- mined in the same way as in the CPM tech- tivity C ends. The critical path is determined nique, using earliest and latest start and in essentially the same way as in other net- finish times, ES, EF, LS, LF. Earliest times are works. In PDM, however, one must account computed by making a forward pass through for the different types of constraints. In this the networks paths, and latest times are example, Activities B (duration=4) and D determined making a backward pass. Fig- 46 ure 6-9 shows the PDM network with these on their path. If Activity B uses 3 weeks of values, using the activity format shown in slack, none will be left for either path. Figure 6-4. The values of ES, EF, LS, and LF in Figure 6-9 represent the beginning of the The above example assumes that progress- unit of work time, in this case a week; e.g., ES ing from one activity to the next requires for Activity A is the beginning of week 1, zero time, which in most projects is unreal- while EF is the beginning of week 6. (The istic. The concept of lag time can be used to beginning of week 6 corresponds to the end incorporate the time required to transition of week 5.) The earliest and latest finish from one activity to another, such as ma- dates for this project , Activity I, is the begin- chine set-up time or movement of material, ning of week 18, or the end of week 17. Using parts, or components from one site to an- the formula for slack, other. Lag time can be shown on the network and must be accounted for in deter- Slack = LS – ES = LF – EF, mining critical path and values of ES, EF, LS and LF. Figure 6-10 shows that in moving we see that on path B – D – G – I, activities B, from Activity D to Activity G, there will be a D, and G each have a slack of 3 weeks. This lag of 1 week. The figure also shows the slack is not additive; if Activity D starts at effect of this lag time on the earliest and week 9 vice week 8, then Activity G has only latest start times and on finish times. The 2 weeks of slack remaining. We also see that resulting slack for Activities D and G is now Activities B, E, and H have 3 weeks of slack 2 weeks. This example shows that the PDM

5 4 5 A C F

4 2 2 B D G

3 I

5 2 E H

Figure 6-8. PDM Example

47 1 6 6 10 10 15 5 4 5 A C F

1 6 6 10 10 15

1 5 8 10 10 12 4 2 2 B D G 15 18 3 4 8 11 13 13 15 I Legend 5 10 10 12

ES EF 5 2 15 18 Duration E H

8 13 13 15 LS LF Figure 6-9. PDM Example—Early and Late Start and Finish Times

1 6610 10 15 5 4 5 A C F

1 6 6 10 10 15

1 5 8 10 11 13 4 2 2 LAG+1 B D G 15 18 3 4 8 10 12 13 15 I Legend 5 10 10 12

ES EF 5 2 15 18 Duration E H

8 13 13 15 LS LF Figure 6-10. PDM Example with Lag Time

FOOTNOTES Note: The numbering convention used in this PDM network is similar to the CPM network in Figure 6-7; it is described on page 46. Each computer scheduling program uses one (or gives a choice) of methods to relate duration to the time unit. 48 technique provides considerably greater flex- and earliest and latest start and finish times, ibility in handling different types of con- represented as the beginning of the unit of straints than does ADM (PERT and CPM). work time (week). Consequently, it is better suited for use in complex projects, particularly those with To determine the adequacy of resources many parallel activities and constraints other (people in this example), assume that each than finish-to-start. activity will start as early as possible and determine the resource requirements over 6.4 NETWORK SCHEDULING WHEN time. Figure 6-12 shows the personnel load- RESOURCES ARE LIMITED ing requirements by time for the duration of the program. During week one, 11 people In the previous discussion, the assumption are required to work on activities A, B, and was that a new activity could start as soon as C. Now, let’s suppose only nine people any constraints were satisfied because suffi- are available to work during this 11 week cient resources were available to perform period. The chart shows there will not be the work. In practice, however, resources to sufficient workers during the first, fourth, proceed are not always available. and fifth weeks. There will be sufficient workers to perform the work In those situations, Program Managers can scheduledduring the second and sixth week. take one or more different actions to reduce During the third and seventh throughout the adverse impact on the program. Those eleventh weeks, there will be a surplus of actions include: workers for the work scheduled. The task becomes one of rearranging the schedule so • Adding additional resources that, insofar as possible, the peaks and val- leys are evened out without scheduling more • Reducing the scope of the program work than nine people can do. In this example, this rearrangement can be accom- • Adjusting the schedule to accommo- plished quickly by hand. However, with date the resource shortfall many activities, it becomes very difficult to find the optimum answer. Fortunately, In this section, we show how network sched- scheduling software applications are avail- ules and the concepts of critical path and able to assist in solving the problem. Re- slack (float) can be applied to make better gardless of the approach used (manual or use of limited resources. Figure 6-11 shows automated), the resource-leveling process is a PDM network with activities A through J. an iterative step-by-step process using a set Each node of the network shows the number of rules to establish the priority of the activi- of people required to complete the activity ties requiring the constrained resource, and along with the activity duration (in weeks) the actions to be taken.

49 1 3 2 A 3 4 5 People 1 8 10 D 2 9 10 4 6 6 10 10 12 2 4 2 E F J 1 4 6 5 4 3 4 6 6 10 B 10 12 6 4 5 5 7 1 4 1 2 G H 3 4 7 8 8 10 4 6 2 I 1 2 4 1 8 10 C 2 9 10 Figure 6-11. Network Schedule with Constrained Resources

16 15 14 D 13 Personnel Shortage 12 H 11 E 10 A Personnel Available 9 8 A 7 E Personnel F 6 Surplus People Required 5 B G 4 3 BB FFF J J 2 IIH 1 C 0 1 2 3 4 5 6 7 8 9 10 11 Time (Weeks)

Figure 6-12. Personnel Loading Chart 50 As discussed earlier, the concept of float (or nel shortage as the project progresses. It may slack) can be useful in the efficient allocation not always be possible to rearrange the sched- of resources, and it should be considered in ule to stay within the resource constraints. establishing the rules to be followed. The In those cases, other steps, such as adding float demonstrated in earlier examples is more resources or extending the schedule, commonly called path float. Another type will have to be taken to minimize the ad- of float that is particularly useful in resource verse impact on the program. allocation is free float. Free float is the slack that a single activity can experience without 6.5 SUMMARY affecting any other activity.1 The free float of a given activity is defined as the difference Network scheduling techniques (PERT, between earliest start of the succeeding ac- CPM, and PDM) are much alike in provid- tivity and earliest finish of the given activity. ing such things as interdependencies, depth In our example, the free float for Activity D of detail, a critical path, and slack. The is FF(D)=ES(J)-EF(D)10-5=5. choice among these three techniques de- In this example, the approach is to find pends primarily on the type of program and activities having the most free float and try managerial objectives. The PERT method is to delay them as long as possible without particularly useful if there is considerable delaying the entire program. By delaying uncertainty in program activity times and if the start of Activity C for 2 weeks (to the control of the program schedule outweighs beginning of week 3), Activities A and B can other factors. On the other hand, CPM is begin simultaneously without exceeding the more appropriate when activity times can limit of nine workers. Similarly, Activities be adjusted readily and when it is important D, H, and I can be delayed, resulting in the to plan an appropriate tradeoff between pro- revised personnel loading chart shown in gram time and cost. The PDM technique is Figure 6-13. best suited for complex projects with different types of relationships/constraints be- Figure 6-14 shows the revised schedule us- tween activities. In reality, the proliferation ing lag times to reflect the delays. Note that of scheduling software has blurred many of Activity A has a start-start relationship with the differences among network scheduling Activity B. The “Lag 0” constraint indicates techniques as well as Gantt and milestone that A should start when B starts. Any delay techniques. in starting Activity A will result in a person-

51 16 15 14 13 12 11 10 9 8 A A G H HII 7 C D 6 People Required 5 4 3 B BBEEFFFFJJ 2 1 0 1 2 3 4 5 6 7 8 9 10 11 Time (Weeks)

Figure 6-13. Revised Personnel Loading Chart

1 3 2 A 3 5 6 People 1 8 10 Lag+1 D 2 Lag 0 9 10 4 6 6 10 10 12 2 4 2 E F J 1 4 6 5 4 3 4 6 6 10 B 10 12 4 5 6 6 8 1 1 4 2 Lag+1 G H 3 4 6 7 8 10 Lag+2 8 10 2 Lag+4 I 3 4 4 1 8 10 C 2 9 10 6-14. Revised Network Schedule with Constrained Resources

52 ENDNOTES

1 Fleming, Bonn, and Humphreys, Project and Production Scheduling, Probus Publishing Co., Chicago, IL, 1987, Chapter 8.

53 7 PRODUCTION SCHEDULING

7.1 DESCRIPTION Production planning and scheduling should be very detailed. A top-level project The scheduling techniques discussed in schedule should serve as the production the previous chapters are best suited for baseline. It should reflect the integration of one-time development projects. Produc- activities that different organizations in- tion scheduling, as its name implies, fo- volved in the production process conduct— cuses on the planning, execution, and con- tooling, material procurement, etc. Lower trol of repetitive activities, such as those tier schedules should be developed for involved in the manufacture of several iden- each of the manufacturing activities, with tical items using the same processes. The special attention to those having potential objective of production scheduling is to impact on the delivery schedule, e.g., ma- balance the materials required to produce terial procurement; tool design, fabrica- the items with the production process and tion, and prove-out; test equipment prove- the delivery schedule. Such scheduling is out; and capital equipment procurement. essential to the efficient use of all resources Thorough planning and integration of all and facilities involved in the manufactur- production process activities are essential ing process. to manage risk in the manufacturing approach. This also provides assurance that While the principles of planning and sched- necessary resources will be available when uling are essentially the same for both situa- needed, that no resources will be over- tions, there are differences that should be loaded or completely expended during considered. For example, in the develop- execution of any manufacturing task, and ment phase, planning and scheduling that product delivery dates are achievable. should reflect the uncertainty inherent in development of the product and processes An understanding of the production pro- used. Consequently, planning and sched- cesses, to include such things as the se- uling should permit sufficient flexibility to quence of operations, make or buy deci- allow for redesign and retest when inevi- sions, inspection methods, tooling, etc., is table problems arise. In production, there critical to effective production planning is less uncertainty; the design is relatively and scheduling. The planning and sched- stable and the processes to be used are uling of all activities must be fully inte- fairly well-defined. In general, more de- grated and reflect a synchronized flow of finitive constraints exist in production events that result in product or process scheduling, such as quantities to be pro- completion when required. The produc- duced, required delivery dates, and cation schedule describing and integrating pabilities and availability of production such things as the acquisition of required assets. materials, fabrication flow, process times,

53 plant facilities to be used, and personnel 7.1.1 Objective Chart skills required should be developed as early as possible in the development pro- An Objective Chart (Figure 7-1A) is a dis- cess and included in the manufacturing play of the cumulative contract delivery plan. schedule over time. It shows cumulative units on the vertical scale and dates of Once the planning and scheduling are com- delivery along the horizontal scale. It also plete and production begins, managers shows actual cumulative deliveries to date. need the means to monitor progress and to identify problem areas in the process that 7.1.2 Production Plan Chart could adversely affect the delivery schedule. A technique that is commonly used for This chart (Figure 7-1B) shows the major this purpose is the Line of Balance (LOB) production process activities and events technique. It graphically portrays the key (control points) that are to be monitored activities of the production plan relative to using this technique. It also shows the lead- a required delivery schedule and provides time associated with each of the control a view of the progress being made in each points. activity. This enables managers to focus their attention on specific problem areas in The more steps that are monitored, the more the process. sensitive and more complicated the chart becomes. Generally, control points on a Government PMs, except those associated single chart should be limited to 50. If there with an activity that builds or re-builds are more than 50, subsidiary production equipment, will never be responsible for plans can be used to feed the top plan. Thus, developing a production schedule. How- each chart can be kept simple and easy to ever, they should understand the process understand. The shipping date of subsid- of creating one because the success of a iary charts is the point at which a subpro- program is very dependent upon the program must be ready to join the overall ducer to plan, schedule, and implement a schedule. production plan. On the production plan chart, each moni- The ensuing discussion provides a basis tored step is numbered, left to right. Step 1 for understanding the fundamentals of has the longest lead time; the shipping date production planning and monitoring. Most is the highest-numbered step. When two companies have tailored planning software steps are done at the same time, they are programs to fit their needs, however the numbered from top to bottom, such as steps principles are the same as those used in the 8, 9, and 10. These control points can also be LOB approach. For that reason, LOB is the given symbols that show whether they in- subject of discussion. volve purchased items, subcontracted parts, or parts and assemblies produced in-house. The LOB technique consists of four ele- Assemblies break down into subassemblies, ments as described below and shown in which break down into parts or operations. Figure 7-1. The application and use of this Thus, one can develop a production plan technique is demonstrated in a later sec- for any part or level of assembly. tion of this chapter. 54 55

Figure 7-1. Line of Balance Technique The production plan chart shows the 7.1.4 Line of Balance interrelationships and the sequence of major steps, as well as lead times required The LOB represents the number of units that for each step. An understanding of the should have passed through each control manufacturing processes involved and point (cumulatively) to satisfy the contract sound judgment are required to know delivery schedule. Managers use it to ana- which step and how many steps must be lyze how the status of each control point on a monitored. Slack or float times for activi- given date will affect future schedules. This ties are not considered when plotting the LOB is drawn on the Program Status Chart production/lead-time chart; only the esti- (Figure 7-1C) using the following procedures: mated time (and latest finish point) for each activity is used. (1) Select a control point; for example, 7.

The 12 control points in the production (2) From the production plan/lead-time plan chart shown in Figure 7-1B represent chart (Figure 7-1B), determine the lead time— key tasks in manufacturing one lot of mis- the time from control point 7 to the shipment siles. The plan indicates that control point point, Government Acceptance (12 (1), fabricate ballistics shell, must begin 24 workdays). workdays before 1 January to meet the first scheduled delivery of five units by the end (3) Using this number, determine the date of December (see the objective chart). The that the unit now at control point 7 should be lead time for other control points can be completed. (May 1 + 12 workdays = just over related to the scheduled delivery in a simi- halfway through a 22-workday month.) lar manner. Time for in-house transfer and storage must be allowed in addition to the (4) Find the point corresponding to this processing time. date, approximately May 17, on the contract schedule line and determine how many units 7.1.3 Program Status Chart scheduled for completion this represents by moving horizontally from the objective chart This chart (Figure 7-1C) shows the cumula- to the program status chart (they share the tive inventory status at each control point in same vertical scale). the process at a given time (in this case, 1 May). Looking at control point 12, we see (5) Draw a line on the program status that the government has accepted 14 units of chart (Figure 7-1C) at the level (43 units) over the product. The bar for control point 9 shows control point 7. that 40 units of the guidance section have been assembled, and the bar for control point (6) Repeat the above for each control 4 shows that in-house fabrication has begun point and connect the horizontal lines over on 60 fins. the control points. The resulting line is the LOB, indicating the quantities of (1) units The cumulative numbers of units through that should have passed through each con- every control point can and should be meas- trol point on the date of the study or inven- ured monthly. Final deliveries (government tory (1 May) if the contract delivery schedule acceptances) are shown month-by-month on were being met. the objective chart as actual deliveries. 56 The difference between the LOB and the 7.2.2 Analysis top of the bar for each control point is the number of units behind or ahead of sched- Using the LOB charts in Figure 7-1, man- ule as of 1 May. Thus, control point 12 is 16 agement can tell at a glance how actual units behind schedule, control point 9 is 5 progress compares with planned progress. units ahead of schedule, and control point Analysis of the charts can pinpoint prob- 7 is 21 units behind schedule. The main lem areas. Delays at control point 7 in the impact of control point 7 being behind example may have been causing final de- schedule will be felt in 12 workdays, which livery problems throughout the contract. is the lead time for control point 7. As of 1 However, the purpose of LOB analysis is April, an insufficient number of air vehicle not to show what caused the slippage in components (shell, fins, engine) had passed the shipping date, but to detect potential into the assembly (air vehicle body) phase. future problems. This will adversely affect final deliveries 12 workdays hence. All other control points In the example, the Government accep- can be analyzed in the same way. tance point is control point 12. The bar doesn’t reach the LOB; therefore, deliver- 7.2 WHEN AND HOW TO USE THE ies are behind schedule. Control points 10 LINE OF BALANCE TECHNIQUES and 11 are short. However, point 9 is on schedule. Since point 10 depends on points 7.2.1 General 8 and 9, we know control point 8 is the offender. Both points 7 and 8 are short, but The LOB technique should be considered there are more than enough purchased for use in any project requiring the manu- items (engines) at control point 6. facture of a specific quantity of a product using repetitive processes. It is an effective What’s the problem with control point 8? technique for identifying those activities Trace it back to control point 7, which is that require attention and possibly correc- seriously short. It is obvious that not hav- tive action and can also be used for reporting enough completed fins is holding up ing the status of the manufacturing process the whole process. Control points 2, 3 and and delivery schedule to higher manage- 5 are short, but are not directly responsible ment. The LOB charts should be updated for the failure to meet the delivery sched- on a periodic basis (weekly or monthly, ule since 9 is ahead of schedule. Neverthe- depending on such factors as the size of the less shortages at 2, 3, and 5 could soon production run, the number of activities/ cause problems at 9. The problem with the control points, and the level of automated fins 7 should be addressed before manage- data management). ment attention is devoted to other short operations. The overages at control points Government managers will probably not 1 and 6 may be examined from the point of be involved with the LOB technique in the view of inventory control. Updating the day-to-day management of their programs. charts requires a good status-reporting sys- However, they should have a basic under- tem, which can be mechanized if the pro- standing of the technique, the type of infor- gram is large and complex. mation it can convey, and its applicability.

57 7.3 LINE OF BALANCE ADVANTAGES Think of the production process as a natu- AND DISADVANTAGES ral gas pipeline. If a bubble of air gets into the pipeline, it will eventually be 7.3.1 Advantages carried to the gas users, and the users will find their burners extinguished as (1) Points out problems before their the nonflammable air reaches them. The impact on finished product deliveries show manager of the pipeline company or the up, thereby allowing managers to correct natural gas utility doesn’t want clients to problems earlier. suffer blowouts from air bubbles in their lines. The same holds true for the manag- (2) Allows managers to see, in the ers of a continuous production process. middle of a contract, whether they can meet Waiting for problems to show up at the the contract schedule if they continue work- end of the line is a mistake. Problems ing as they have been. need to be detected when they begin so corrections are faster, before too much (3) Focuses attention on those pro- damage (to cost, performance, or sched- duction control points where there are prob- ule) is done, and production schedules lems; this allows a senior manager to pinpoint responsibility for slippages. fall too far off contract.

7.3.2 Disadvantages To do LOB, the following is needed: (1) a contract schedule, or objective chart; (2) a (1) People working on a project may production plan or lead-time chart for not grasp what the LOB is measuring. the production process itself; (3) control points cumulative inventories; and (4) a (2) Limited to production and/or program status chart on which to plot assembly-type processes. LOB and the cumulative quantities of units that have passed through the con- (3) Shows only where the problem is, trol points of the assembly/production not what it is. process. If the objective and program status charts are given the same vertical (4) A monitoring device; not as easy scale, the LOB can be plotted graphically to use as a planning device. from the former to the latter.

7.4 SUMMARY Remember that the shape of the LOB will change over time, especially if the The LOB is a monitoring technique that production process has a beginning and gives prior warning of problems within a an end. Remember, too, that LOB charts continuous production process. The key is show where a problem is, but not neces- to catch problems in a production process sarily why the problem exists or what the early; otherwise, the schedule is lost. The solution is. LOB technique provides that warning.

58 8 TIME MANAGEMENT

In most programs, especially in DoD and (1) Most PMs establish a time reserve of defense-related industries, time is a re- about 10 percent. On a 40-month program, source that must be carefully managed. If for example, a 4-month time reserve would it is not, it can become a serious constraint be established. that can threaten the success of the program. This chapter addresses time man- (2) The time reserve must be held closely agement from two perspectives: first, as it by the PM. Otherwise, every manager on relates to a program, and second, as it his/her program may think “I know there’s relates to the PMs use of time. a time reserve; therefore, I don’t really have to meet my schedule.” The PM may place 8.1 TIME MANAGEMENT AND this reserve under “additional system tests” THE PROGRAM or another downstream activity. The point is, it shouldn’t be visible. (A built-in safety This section concerns three aspects of time factor between the manufacturing sched- management related to programs: ule and the delivery schedule is often used.)

(1) Time reserve (3) A tough and disciplined approach to meeting the published schedule is required (2) “Now” schedule from the start of a program in order to maintain the reserve and, consequently, to (3) Value of time. meet the program schedule in spite of slippages caused by the unknown unknowns 8.1.1 Time Reserve (unk-unks) that inevitably arise.

In contractor performance measurement, 8.1.2 “Now” Schedule much emphasis is placed on “management reserve,” the reserve budget controlled by There is a direct relationship between time the industry PM. What isn’t always recog- and cost for any activity. This relationship nized is that a time reserve is also needed in takes into account the people, resources, order to accommodate unknowns in the pro- and method used. It also considers the gram. However, use of a time reserve should efficiency achieved. Generally, the least be approached with caution, because mem- costly schedule is the current one. Speed- bers of a program office team may be tempted ing up the schedule costs more; stretching to fall back on it prematurely. out the schedule also costs more.

Literature describing time reserve is scarce. The sum of the direct and indirect costs However, there are some aspects of a time gives a U-shaped total program cost curve. reserve that are clear. 59 The optimum schedule for implementing Often, the organization causing a slip in the program is the schedule correspond- schedule becomes a repeat offender. The ing to the minimum point on this curve. principal value of retaining a former sched- The relationship among direct, indirect, ule lies in being able to hold the offender’s and total program cost is shown graphi- feet to the fire, thus making schedule cally in Figure 8-1. slips less palatable.

Because schedule stability affects program The significance of maintaining a stable costs, which may, in turn, affect technical schedule is becoming more widely recog- performance, it is clear that schedule sta- nized. Appendix A describes the develop- bility has a great deal to do with whether ment of a master schedule and the impor- the program meets its cost and technical tance of maintaining schedule discipline. objectives. Unfortunately, budget constraints and other factors, like changes in 8.1.3 Value of Time quantities (items over which the PM has no control), have often been imposed on a According to the late John H. Richardson, program with the comment, “Do the best president of Hughes Aircraft Company, you can.” “A basic reason for adopting project (or program) management, when tackling the When a schedule must be revised, the difficult and unique tasks associated with superseded schedule is often discarded. If developing and producing a system, is to the new schedule is superseded, the pro- eliminate unnecessary delays in accom- cess is repeated. However, there is some plishing the job at hand. Time is a resource value in retaining an obsolete schedule. in systems management, to be treated with

Total Program Cost

Indirect Cost Program Cost Direct Cost

Optimum Time

Figure 8-1. Total Cost Analysis for Selecting “Optimum” Program Duration

60 indifference or used well like any other forgotten is the fact that a month’s delay in the resource. For projects not yet in full swing, early stages of development is exactly as it is important to recognize that time has long as a month’s delay in the later stages. economic value, and that we may be taking While it may seem innocuous to put off a time too much for granted.”1 decision for a month or two in the early years of a project (or program) with an uncertain (1) Funding could create a problem. In future, that delay may turn out to be just as hungry years, the schedule is often costly as is procrastination when the final stretched because of reduced funding. decisions are made. In short, a sense of ur- gency is essential to decision making in all (2) A better product could be developed stages of a new venture, not just the later if it were more thoroughly debugged and stages.”3 tested. However, a system does not really get wrung-out until it is in the user’s hands, The useful life of a defense system must be regardless of advance debugging. taken into consideration. Concentration on the system or product often overlooks a key (3) Cost of concurrency (overlap of devel- point: whether the buyer obtains value upon opment and production) might lead to a delivery. The most costly product is one that decision not to overlap program phases. appears when it no longer fulfills a useful Such a decision might be popular in many purpose, even though it has been produced cases, but it could never be tolerated when at minimum cost. Each month added to the the pendulum swings toward the impor- development and production of a new high- tance of time; that is, when top manage- technology system or product tends to re- ment says, “Get the system out the door, duce by 1 month the operational life of the never mind what it costs.”2 system or product.

Stretched-out schedules incur cost penal- In spite of the 10-20 percent cost premium ties because of inflation, additional engi- that may be paid for tight scheduling (as neering changes, and changes in key pro- compared to orderly but stretched-out sched- gram management office positions. An- uling), the resulting longer operational life other near-term cost is due to the increased may provide greater economic value. This is chance that a program will be canceled looking at time only from the viewpoint of because of obsolescence or competing tech- economics, i.e., acquisition cost per year of nology. Stretch-outs invite cancellation. operational availabil survival insurance. Also, long schedules with no opportunities for incorporation of improvements are Consideration of alternative plans and sched- a negative factor when considering a new ules will also help; e.g., if event so-and-so start. occurs, proceed with plan A; if event such- and-such occurs, proceed with plan B and so Delayed decisions increase costs. Accord- on. Anticipation and preparation for most- ing to R. W. Peterson, former DuPont execu- likely events, along with the tools described, tive, “All businessmen are concerned, and and coupled with effective communication properly so, about the long time it takes to of the plans, can change the management move a new development from its incep- style from crisis management to skillful tion to a profit status. But frequently management. 61 8.2 TIME MANAGEMENT AND THE inability or reluctance to say no. If a subor- PROGRAM MANAGER4 dinate brings a problem to the PM, the Manager must be alert to make sure not to PMs are busy people. They have the re- assume responsibility for the problem, sponsibility for the management of a unless, of course, the situation warrants myriad of activities and the resources that such action. If subordinates believe that make up the program. In addition, they are PMs will assume responsibility for their often required to perform specific program problems, needless demands on the PM’s activities, especially in smaller programs. time will increase. Thus, it is important that they manage their time well. Some managers could be more Meetings are a fact of life in program man- productive, perhaps as much as 20-40 per- agement. However, unless they are effec- cent, by better managing their time. A ma- tively planned and conducted, they can be jor difficulty in accomplishing this is the a severe drain on time and resources. A failure to realize that there is a time man- number of common pitfalls, if not avoided, agement problem and that solutions are can turn meetings into a complete waste of possible. This section discusses various time. Among them are: not having a clear aspects of time management and identifies and focused agenda; spending too much ways to better accomplish it. time on trivial matters; having too many or too few meetings; not having the right In the early 1980s, a time management sur- people at the meetings; and not keeping an vey was conducted to identify the prob- accurate record of decisions and actions lems in achieving effective time manage- assigned. ment. More than 300 project managers in 24 industries, including the government, par- To get the most value out of meetings, the ticipated in the survey, which investigated following actions should be considered: 15 different areas. The survey identified several time management problem areas. (1) Understand the purpose of the meeting Among the most common were time rob- and what results are expected bers and meetings. (2) Minimize the number of people attend- Time robbers are simply those things that ing the meeting can occur on a day-to-day basis that can take away from the PMs ability and time to (3) Hold the meeting in a setting appro- accomplish his/her work. There are liter- priate for the meeting objectives ally dozens, if not hundreds, of such things, such as incomplete work, delayed deci- (4) Develop and distribute the agenda sions, poor communications channels, casual visitors, lack of effective program (5) Start and finish on time management tools, etc. Appendix B contains a list of common time robbers. The (6) Summarize meeting results and pre- survey found that delayed decisions and pare and distribute minutes. poor communications were the most commonly cited time robbers. Another com- In addition to focusing on time robbers mon problem that affects a PMs time is the and the conduct of meetings, PMs should 62 also concentrate on other effective time make the least desirable decision because management techniques, such as: of lack of time. Establishing a time reserve and a “now” schedule, and recognizing the (7) Prioritize activities value of time in decision making all con- tribute to the PMs repertoire of good tools. (8) Devote solid time blocks for important activities Sir Jeffrey Quill, manager of the British Spitfire Development Program, com- (9) Maintain “to do” lists and time logs mented during a visit to DSMC that; “After 1935, costs weren’t particularly important. (10) Delegate What mattered was time. We worked three shifts a day. Everything was time. Quan- (11) Manage by exception tity and time. It turned out that we probably produced at the lowest cost, too; but (12) Practice calculated neglect the emphasis was on time.”

(13) Control access—limit casual visits PMs must manage their time effectively if and telephone calls. they are to be successful. They must be alert to those time robbers that affect their 8.3 SUMMARY ability to accomplish their work and understand the value of proven time manage- Planning and scheduling can do much to ment techniques. prevent running out of time and having to

63 ENDNOTES 1 John H. Richardson, Time Defeats Technology, Hughes Aircraft Company, Culver City, Calif., date unknown. 2 Ibid. 3 Russell W. Peterson, former DuPont executive, Governor of Delaware and White House advisor, “New Venture Management in a Large Company,” Harvard Business Review, May-June 1967, p. 72. 4 Harold Kerzner, Project Management, Van Nostrand Reinhold, New York, 1998, Chapter 6.

64 9 AUTOMATED SCHEDULING TOOLS

Previous chapters have shown that manag- 9.1 AUTOMATED PLANNING AIDS ers use schedules in a variety of ways for a wide range of purposes. Schedules are an The idea to use the power of the computer integral part of the program planning and to assist in the planning and tracking pro- decision processes. Managers use them to cess is not new. Industry has used auto- track progress, predict future work, man- mated scheduling software for at least the age resources, analyze alternatives, iden- past 30 years. Early versions of these tools, tify risk, and report program status. In however, usually employed a mainframe most cases, it is the PMs responsibility to computer that batch processed data off- construct, revise, maintain, and report line and spewed reams of information for schedule information. managers to analyze when they arrived at work on a Monday morning. Despite the The PM must do these things in a complex automated tools, the process of creating, environment that cuts across contractor and maintaining, and reporting schedule infor- government boundaries and includes a mation was a daunting task. wide geographical area. The challenge is complicated even further by the need for The advent of PCs/workstations and net- instant information that must be available work technologies has made life easier for to a wide audience that usually requires managers. The market encourages soft- the information in a specific format to suit ware vendors to develop a wide range of unique needs. programs readily available to P Ms to aid them in effectively and efficiently dealing It would be impossible to meet these chal- with the details involved in creating a pro- lenges without automated tools.The gram plan, then tracking progress. remainder of this chapter discusses characteristics and features of some tools avail- The introductory paragraph of this chap- able on the market today and suggests ter lists many uses of a “schedule.” Soft- criteria that anyone searching for a tool ware developers have responded to the should consider. The intent is to provide managers’ needs by creating programs an overview of the types of products that that build schedules and support pro- are available and the range of functions gram management functions. Even the these products support. The level of detail simplest program includes some program presented is keyed to what would be use- management features. The focus of the ful to know about the program manage- following discussion, therefore, is on the ment software tools that would likely be broad category of Program (often called used in a mid-to-large Program Office. Project) Management Software.

65 The focus is on providing a brief descrip- (1) System-Level Characteristics tion of the functionality of these products, highlighting some of the desirable features (2) Project Management/Scheduling that are available to support program Characteristics management, and identifying sources that may be useful in determining what prod- (3) Ease of Use. ucts are available and how their features and performance might be assessed. System-level features have a general applicability, independent of any of the 9.2 FUNCTIONAL CHARACTERISTICS specific project-management activities sup- AND FEATURES ported, that add to the overall capability and desirability of the product. These fea- Most of the Program Management Soft- tures include, but may not be limited to: ware that is available today is based on a relational database design and is therefore • Collaboration/Workgroup—Enables able to support a broad range of program managers/team members to use a com- management activities including: mon system of communication and allow access to common databases for the pur- (1) Scheduling/Tracking pose of assigning tasks, updating project data, assigning resources, and reporting (2) Resource Planning/Management status.

(3) Risk Management • Integral e-mail—Allows exchange of messages and file attachments to other (4) Cost/Performance/Analysis project team members from within the project management application. (5) Reports and Graphics. • Multiple Project/Multiple Tasks—Sup- The extent to which the different programs ports multiple programs and tasks within support these activities varies from prod- a project. uct to product. For example, some products provide the capability to create only • Security—Limits access to certain data Gantt charts whereas others provide the by individual or class of user, as well as tools to make Gantt and network charts. password protection for the system.

Program features, the way in which activi- • Open Data Base Connectivity ties are implemented, are an important (ODBC)—Enables users to import data factor in considering the usefulness of a from other data sources and in various program. A convenient way to profile the formats into their scheduling applications functional characteristics and associated (e.g., data from your contractor’s project features of automated program manage- database). This is a Microsoft-developed ment tools is to do so from these three standard for exchanging data with a vari- perspectives: ety of databases.

66 Most programs include features that focus • Import/Export—Import/Export data on program management and schedule from/to an external source, such as an- functions. Some features offered are: other database or spread sheets, facilitates the ability to create custom reports or con- • Project Scheduling/Tracking—Data duct analyses. Entry Templates facilitate the entry of the initial task, time, and resource data. On- Finally, ease of use or user friendliness, is Screen Tracking facilitates comparison of the set of qualities that represent the de- actual performance versus the planned and gree in which people can employ the soft- allows tracking of progress by cost, time, ware without an inordinate amount of train- or achievement. ing or regular reference to user’s manuals. User friendliness is an important consider- • Resource Planning/Management—Re- ation because program management soft- source Leveling is a capability that resolves ware products can be complicated. Re- resource conflicts by delaying tasks and gardless of how powerful a program may assignments as well as by task splitting, be, if it is difficult to use, managers prob- which entails dividing tasks into segments ably will not spend the time to learn it. with time gaps as necessary. Resource Cal- Consequently, PM software is likely to be endars provide insight into the availability effective and desirable if users can easily of a particular resource by showing work- learn to use it. ing and non-working times. Free/Total Slack Time is a feature that is useful for adjusting The following features typify user-friendly under-or-over allocated resources. systems:

• Cost/Performance Analysis—Earned • Graphical User Interfaces (GUIs)— Value Tools are essential for comparing ac- These are the screens in which a user inter- tual performance with expected perform- acts with the program. The operating envi- ance. Cost Analysis Tool Kits are tools for ronments in use today have led to the analyzing data and making forecasts. This development of interface screens that en- feature may be integral to the product or able the user to interact with the software in available by virtue of “exporting” data to an intuitive way, using a variety of but- another application with this capability. tons, menu lists, and wizards.

• Reports and Graphics—Pre-Defined Re- • On-Screen Data Entry—The capability ports facilitate the presentation of project to create schedule information by using data. Customization Controls provide users tools to create an on-screen graph. See Fig- with a convenient way to format reports to ure 9-1 for an example. their own specifications. Filters enable the user to screen information, e.g., tasks or • Help Function—On-screen docu- resources, before capturing a screen-view mentation as well as “context-sensitive” or preparing a report. Embedded Graphics help in which the software displays the and Text capability allows a user to import applicable text based on the functions be- data from other applications for inclusion ing performed. This is a particularly useful in a project report. feature for someone learning to use it.

67 Figure 9-1. On -Screen Data Entry Using Gantt Chart Feature (AEC Software Fast Track Schedule)

• Tutorials—Program instruction on per- 9.3 EVALUATING PROJECT forming certain functions and guidance MANAGEMENT SOFTWARE through a “canned” demonstration. PRODUCTS

• Wizards—Templates that guide the Choosing a software program from the user through various project setup, data wide range of available products can be entry, and report formatting procedures. complex and time consuming. The selec- The features discussed above are a sample tion process should begin with an analysis of the characteristics of various program of what managers want to do with the management products. Moreover, there is software to identify the functions that are no common “feature list” or set of defini- needed. Other factors that should be part tions that defines the various characteris- of the assessment process are consider- tics. Nonetheless, the summary should give ation of personnel skill levels/training re- a sense of what is available and provide the quirements, integration with enterprise basis for a more exhaustive review as (organizational) systems, hardware/sys- needed. tem requirements, and cost. 68 Table 9-1. Project Management Software Functions and Criteria

USER FRIENDLINESS Feature Consideration Graphical User Interfaces (GUIs) Logical, intuitive, all inclusive, windows compliant Robust Help Function Complete, easy to access, context based, examples Wizards Exist for major functional areas, intuitive, tailorable results Tools Exist for major functional areas, intuitive Tutorials Complete and examples On-Screen Data Entry Simple, logical, complete, intuitive SYSTEM LEVEL FEATURES Collaboration/Workgroup Support Desired capabilities available, non-proprietary Integral e-mail Exists, simple, compatibility with existing e-mail Multi-Project & Task Support Roll-up to higher levels, supported by reporting features Security Meets specific security needs, compatible w/ existing system Open Data Base Connectivity Data transfer with other program management S/W PROJECT MANAGEMENT/SCHEDULING FUNCTIONS Project Scheduling/Tracking Multiple Schedule Methods Create Gantt, network charts, and go from one to the other Roll-Up Display and report different levels Ability to Tailor to Specific Needs Add/delete/modify activity and event information Relationships Display and report dependencies among events/activities Progress Tracking Compare and display plans and actual progress Critical Path Display Highlight critical path Interoperability w/ Other Programs Import and export data from other programs Total Free/Slack Time Compute and display free and slack time Time Estimates Use probability distributions to compute time to complete Time Roll-Up Use statistical methods to compute roll-up times Resource Planning/Management Resource Determination Assist in determining resources needed Resource Assignment Allow assignment and notification of assignment to activities Interoperability w/ Other Programs Import and export resource data Resource Leveling Easy to access, permits “what if” excursions Resource Calendars Display resources over time Task Assignment Filter and display assignment of responsibility Analysis Schedule Analysis Allow analysis and comparison of alternative schedules Earned Value Analysis Assist in complete and accurate EV analysis Cost Analysis Includes tool kits for analysis of program cost Resource Analysis Compute resource utilization, identify conflicts Reports Pre-Defined Report Formats Automatically create reports based on program data Customization Controls Allow reports to be tailored for specific purposes Embedded Graphics and Text Add text and graphics to reports 69 Analyses of requirements and software offices are going to share information, it is evaluation are beyond the scope of this prudent to use the same software, if pos- discussion. However, Table 9-1 shows sible. At the very least, compatibility and some of the functions that are available in interoperability must be demonstrated be- available program management software fore making a decision to buy a particular and lists some ideas for consideration when product. searching for the right software. There is a considerable information on 9.4 FINDING OUT MORE project management and scheduling software from a variety of sources. The Defense The best method of gaining information Acquisition Deskbook (DAD) has a list of tools about a potential project management tool that are being used by program offices. is to talk to someone who is using the From a commercial aspect, specific prod- product. A PM in the next office may have uct information is available on most com- a perfectly acceptable and proven product panies’ World Wide Web home pages. that he/she is using. The company under Virtually all developers provide informa- contract may have a product that it uses. If tion about their products on a web site and the government and contractor program show links/contact to additional sources.

70 APPENDIX A

INTEGRATED MASTER SCHEDULE DESCRIPTION

The Integrated Master Schedule (IMS) for a format that greatly facilitates the tracking program should be a time reference and execution of the program. baseline for the activities and events that make up the program. It should be incor- In some cases, a preliminary IMP and its porated into the program plan and linked corresponding IMS may be developed by to approved performance and cost objec- the government but include industry in- tives. The IMS is developed by the contrac- puts obtained through open communica- tor from the Integrated Master Plan (IMP), tions with potential sources during the which documents all the tasks required to pre-solicitation phase of the acquisition. deliver a high quality product and to facili- Contractors are normally required to sub- tate success throughout the product’s life mit formal IMP and IMS with their propos- cycle. In an Integrated Product and Process als and to develop more detailed IMP/ Development (IPPD) environment, which IMS versions after the contract is awarded. is the standard approach for all DoD programs, the IMP and IMS provide an The IMS is event driven and is developed overarching framework against which the with participation of all program stake- Integrated Product Teams (IPTs) can func- holders. It should identify all tasks that tion, helping them understand their work need to be accomplished, their logical or- within the context of the total program. der, and the input conditions necessary to complete each task. When documented in The IMP and IMS evolve as the program a formal plan and schedule, this event- matures. During the initial stages of Con- driven approach can help ensure that all cept Exploration, the integrated plan is tasks are integrated properly and that the preliminary and its purpose is to provide management process is based on signifi- an understanding of the scope of work cant events in the acquisition life cycle and required and the likely structure of the not on arbitrary calendar events. Develop- program. It is constructed to depict a likely ing the program schedule presents an op- progression of work through the remain- portunity to identify critical risk areas. As ing phases, with the most emphasis on the IPT members estimate the times to com- current and/or upcoming phase (especially plete specific tasks, events that may cause the period to be contracted for next). As the delays will become apparent. These events program is defined, the IMP is iterated are potential areas of risk that the IPT several times, each time increasing the level should consider for further analysis. of detail and confidence at which all essential work has been identified. The specific The IMS begins as an IMP with dates—the format for this plan is not critical; however, starting points are the events, accomplish- it usually reflects an Event/Accomplish- ments, and criteria that make up the plan. ment/Criteria hierarchical structure—a At a minimum, an IMS shows the expected 71 start and stop dates for each activity in the they were obtained at the right time. In plan, but each activity may be broken down addition, the IMS can be useful for the into lower-level tasks that will be used to following events/activities that are com- manage the program on a day-to-day ba- mon to all programs. sis. The schedule can be expanded down- ward to the level of detail appropriate for PROGRAM REVIEWS the scope and risk of the program. Pro- grams with high risk show much lower The IMS can be a framework for periodic levels of detail in the integrated master program reviews within the program man- schedule in order to give the visibility agement office (PMO). If constructed prop- necessary to manage risk. The more de- erly, the schedule will illustrate the vari- tailed the IMS, however, the greater the ous levels of the program and will be com- cost to track and update the schedule. patible with the program cost/schedule Under acquisition reform initiatives, the control system reports. dates in the IMS usually are not made contractually binding so as to allow the Program reviews can be an excellent forum flexibility to take full advantage of event- for resolution of schedule conflicts and the driven scheduling. genesis for controlled changes to the schedule from within the PMO. Most key mem- Additional information on the development bers of the PMO team are present at these of IMSs can be found in various sections of reviews; therefore, proposed schedule the Defense Acquisition Deskbook and in the changes or slips can receive wide dissemi- DoD Integrated Product and Process Develop- nation within the organization. ment Handbook dated August 1998. Com- mercial standards EIA 632 and IEEE 1220- WHAT IF” EXERCISES 1994 can also be consulted for more information on developing master plans and The IMS can serve as the framework for schedules. See http://www.eia.org/eng/ “what if” exercises imposed on programs published.htmandhttp:// from outside the PMO. Schedule changes standards.ieee.org for information on can be plotted manually by using over- how to obtain these standards. A DoD lays. Using the same grid coordinates on Data Item Descriptor (DI-MISC-81183A) an overlay allows the PMO team to see, has been developed for IMS guidance; clearly and graphically, the effect of the it is attached to this Appendix as Tab 1. compressions or extensions of sub-milestones on the program. It may be even USE OF INTEGRATED MASTER easier (and more productive) for the PMO SCHEDULES team to run “what if” exercises on a com- puterized schedule. Without a master The primary purpose of the IMS is to track schedule as a baseline, these exercises can schedule variations. By linking the IMS to take longer to accomplish and they may the IMP, it can also be used to track the overlook important variances from the activities that provide functional and life- program’s established baseline schedule cycle inputs to product development. In or plan. this role it provides a crosscheck not only that the inputs were obtained, but also that 72 PROGRAM BRIEFINGS justification and an understanding of the impact of the changes on the overall pro- The IMS can serve as a baseline for program. Following are examples of some gram reviews at higher headquarters and simple procedures that, if practiced, will other reviews or briefings outside the PMO. instill discipline and prevent the unautho- Most programs have key milestones taken rized release of schedule information that from the master schedule and presented in has not been approved for inclusion in the summary form on viewgraphs or slides. If IMS. these do not show the detail required to make a point, the time span shown can be • Program changes, whatever the source, reduced to the point where the details should start as proposals and, if approved, become visible. grow into a firm plan. Eventually, they are incorporated into the IMS as changes. The SCHEDULE DISCIPLINE question of when to plot these changes is a matter of judgment and should reflect the To be effective, an IMS must be kept up- PM's policy. Each change should be plot- to-date and accurate. Maintenance of the ted as a proposed or tentative change until IMS requires a process similar to that approved. inherent in configuration control—one that establishes discipline through a set of • A permanent record of each change rigorous procedures for managing sched- should be maintained. If the program ule change. The degree of schedule disci- schedule slips, it should be documented pline imposed within the PMO can be a until documentation no longer serves a major factor in the success of a program. useful purpose. The underlying philosophy of the schedule control process should reflect central- • Whenever copies of the IMS are made, ized control of the IMS. That is, changes to they should be dated and authenticated by the IMS baseline should be made only the signature of the PM or the appointed with the approval of the P2M or his/her schedule manager. Undated and unauthen- designated representative and with full ticated schedules should not be released outside the PMO.

73 Form Approved DATA ITEM DESCRIPTION OMB NO. 0704-0188 Public reporting burden for this collection of information is estimated to average 110 hours per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. 1. TITLE 2. IDENTIFICATION NUMBER Integrated Master Schedule (IMS) DI-MISC-81183A 3. DESCRI PTI ON/PURPOSE The IMS is an integrated schedule developed by logically networking detailed program activities. The contract Integrated Master Plan (IMP)is the foundation of the program schedule and provides a hierarchy for schedule traceability and summarization. IMP events, accomplishments, and criteria are included in the schedule to monitor progress. This information will be used to verify attainability of program objectives, evaluate the progress of the government and contractor team toward meeting the program objectives, and to integrate program schedule among all related components. 4. APPROVA L DATE (YYMM DD) 5. OFFI CE OF PRI M ARY RESPONSIBI L I TY (OPR) 6a. DTIC APPLICABLE 6b. GIDEP APPLICABLE 960209 F/ASC/FMCS 7. APPLICATION/INTERRELATIONSHIP 7.1 This Data Item Description (DID) contains the format and content preparation instructions for the data product generated by the specific and discrete task requirement as delineated in the contract. 7.2 This DID may be applied to programs which utilize the Work Breakdown Structure (WBS) during the concept exploration, demonstration and validation, engineering and manufacturing and development, and production phases. 7.3 This DID supersedes DI-MISC-81183.

8. APPROVAL LIMITATION 9a. APPLICABLE FORMS 9b. AMSC NUMBER F7180

10. PREPARATION INSTRUCTIONS 10.1 Format . This precedence logic diagram shall be in the contractor’s format in the form of a network, milestone, and Gantt chart. This diagram shall be provided in digital format. 10.2 Content . The schedule shall contain all of the contract IMP events and milestones, accomplishments, criteria, and activities from contract award to the completion of the contract. The schedule shall be an integrated, logical network-based schedule that correlates to the program WBS, and is vertically and horizontally traceable to the cost/schedule reporting instrument used to address variances (such as Cost Performance Report (CPR), Cost/Schedule Status Report (C/SSR), etc.) It shall have a numbering system that provides traceability through the IMP and Statement of Work (SOW). It shall contain program events and milestones and definitions, summary, intermediate and detailed schedules, and periodic analysis of progress to date. It shall be possible to access the information by product, process, or organizational lines. Descriptions of the key elements are as follows: 10.2.1 Program milestones and definitions. Key programmatic events defined by IMP, the contracting agency or weapon system contractor which define progress and completion in each WBS element along with the definition for successful completion of the milestone. 10.2.2 Summary master schedules. A graphical display of top-level program activities and key events and milestones of the IMP which depict major work activities in an integrated fashion at the summary level of the WBS, e.g. level 1-3 of the WBS. 10.2.3 Intermediate schedules. A graphical display of top-level program activities and key milestones which includes all associated accomplishments of the IMP, traceable to the WBS element as necessary to display the work effort at the intermediate level of summarization, e.g. level 3-5 of the WBS as appropriately tailored. 10.2.4 Detailed schedules. A graphical display of detailed activities and milestones which depict work activities in a particular work breakdown structure element, to include the criteria associated with each accomplishment of the WBS element as well as any additional activities necessary to display the work effort to detailed WBS levels, e.g. level 4-8 of the WBS as appropriately tailored.

11. DI ST RI BUT I ON ST A T EM ENT Distribution Statement A: Approved for public release; distribution is unlimited.

DD Form 1664, APR 89 Previous editions are obsolete Page 1 of 3

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Block 10, Preparation Instructions (Continued)

10.2.5 Periodic analysis. A brief summary which identifies progress to date, variances to the planned schedule, causes for the variance, potential impacts and recommended corrective action to avoid schedule delays. For each program milestone planned, forecasted and actual completion dates shall be reported. The analysis shall also identify potential problems and a continuing assessment of the network critical path. Thresholds for impact reporting shall be identified on the DD Form 1423, CDRL. 10.2.6 Integrated program network. Logical diagram of all activities in the program. The key elements of the integrated network to be constructed in the diagram are as follows: a. Milestone or event - A specific definable accomplishment in the program/project network, recognizable at a particular point in time. Milestones are numbered and may be contained within an activity box. b. Activity or task - A time consuming element, e.g. work in progress between interdependent events, represented by an activity box. c. Duration - Planned length of time needed to accomplish an event/activity. d. Relationships - A line that defines how two activities or events are logically linked. It can take up to four (4) forms:

(1) FS (finish to start) - An activity must finish before another can start.

(2) SS (start to start) - An activity depends on the start of another activity.

(3) FF (finish to finish) - One activity cannot finish until another activity is finished.

(4) SF (start to finish) - An activity cannot finish until another activity starts. e. Slack or Float - Extra time available on an activity before it will impact an activity on the critical path. f. Lag - The delay or wait period between two tasks. g. Critical Path - A sequence of activities in the network that has the longest total duration through the program or project. Activities along the critical path have zero or negative slack/float. It should be easily distinguished on the report formats, e.g. a thick line, patterned or in red ink. This should be calculated by computer-based software. h. Target Start (TS) - A program defined date of when an activity should start. This is an operator- defined date rather than a computer-calculated date. i. Target Complete (TC) - A program defined date of when an activity should finish. This is an operator- defined date rather than a computer-calculated date. j. Actual Start (AS) - Actual start date of an activity. k. Actual Finish (AF) - Actual finish date of an activity. l. Early Start (ES) - The earliest start date an activity can begin the precedence relationships. Computer- calculated date. m. Early Finish (EF) - The earliest finish date an activity can end. Computer-calculated date. n. Late Start (LS) - The latest start date an activity can start without delaying the program or project target completion date. Computer-calculated date.

75 04/15/91 DI-MISC-81183

Block 10, Preparation Instructions (Continued) o. Late Finish (LF) - The latest finish date an activity can have without affecting the program or project target completion date. Computer-calculated date. p. Percent Complete (PC) - Actual progress of an activity from its start to its finish.

10.3 Master Integrated Program Schedule. It shall display all of the proposed activities, events, and milestones from contract award to the completion of the contract.

10.4 Descriptive titles. Activities, tasks, events, and milestones shall be labeled with a brief descriptive title, numbered of coded and contain time constraints (e.g. duration, TS, ES, EF, LS, LF, etc.). Standard abbreviations may be used to conserve space. Descriptive titles used on activities, events, and milestones shall be identical on all program schedules. A legend shall be provided to aid in ease of reading the schedules.

10.5 Schedule risk. The schedule shall include a description of the approach that will be taken to limit the schedule risks identified as a result of the contractor’s risk assessment. Risk shall be defined considering impact on cost and technical performance and assessing the probability of schedule change. Additionally, technical performance measurement tasks and their correlation with contractual cost/schedule elements permit assessment of the program effort in terms of the schedule as well as cost of work increments. As technical performance measurement tasks, as well as cost reviews, reveal potential impacts to the schedule these risks will be identified.

10.5.1 Schedule Risk Assessment (SRA). Optimistic, pessimistic, and most likely durations for each MIPS activity/task and milestone/event shall be provided as the basis for determining the probability of meeting schedule dates. The government will assess the durations and use an appropriate cumulative probability (0-100%) for the chosen milestones to determine expected completion dates.

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76 APPENDIX B Common Time Robbers1

• Incomplete work • Misplaced information • A job poorly done that must be done • Record keeping over • Shifting priorities • Poor communications channels • Indecision or delaying decisions • Uncontrolled telephone calls • Procrastination • Lack of adequate responsibility and commensurate authority • Setting up appointments • Poor functional performance and • Too many meetings status reporting • Monitoring delegated work • Changes without direct notification/ explanation • Unclear roles/job descriptions • Casual visitors and conversations • Unnecessary crisis intervention • Waiting for people • Need to get involved in details to get job done • Failure to delegate, or unwise delegation • Not enough proven or trustworthy managers • Poor retrieval systems • Vague goals and objectives • Lack of information in a ready-to-use format • Too many people involved in minor decision making • Day-to-day administration • Lack of technical knowledge • Spending more time than anticipated in answering questions • Lack of authorization to make judgment decisions • Late appointments • Impromptu tasks • Unreasonable time constraints • Having to explain “thinking” to • Lack of commitment from higher superiors authorities • Too many levels of review • Too much travel

• Too many people in a small area • Lack of adequate project management tools

77 • Poor functional communications/ writ • Dealing with unreliable subcontractors ing skills • Personnel not willing to take risks • Inability to relate to peers in a personal way • Demand for short-term results

• Rush into decisions/beat the deadline • Lack of long-range planning

• Lack of reward (“a pat on the back can • Being overdirected do wonders”) • Overreacting management • Expecting too much from one’s staff and oneself • Poor lead time on projects

• Going from crisis to crisis • Documentation (reports/red tape)

• Conflicting directives • Large number of projects

• Fire drills • Inadequate or inappropriate require ments • Lack of privacy • Desire for perfection • Lack of challenge in job duties • Lack of dedication by technical experts • Bureaucratic roadblocks (“ego”) • Lack of project organization • Empire-building line managers • Constant pressure • Too much work for one person to handle effectively • Constant interruptions

• Excessive paperwork • Project budget problems

• Lack of clerical/administrative support • Shifting of functional personnel

• Workload growing faster than capacity • Lack of qualified manpower

ENDNOTES 1 Harold Kerzner, Project Management, Van Norstand Reinhold, New York, NY, 1998, Chapter 6. 78 APPENDIX C GLOSSARY

ACQUISITION STRATEGY — A busi- ages, etc.) scheduled to be accomplished ness and technical management approach (including in-process work packages), plus designed to achieve program objectives the amount of level of effort and appor- within the resource constraints imposed. It tioned effort scheduled to be accomplished is the framework for planning, directing, within a given time period. (Planned Value) contracting for, and managing a program. It provides a master schedule for research, BUDGETED COST OF WORK PER- development, test, production, fielding, FORMED (BCWP) — A measurement of modification, postproduction manage- work performed in cost/schedule control ment, and other activities essential for pro- systems criteria (C/SCSC) terminology. gram success. Acquisition strategy is the BCWP is a measurement of work per- basis for formulating functional plans and formed as compared to the original plan. strategies [e.g., test and evaluation master (Earned Value) plan (TEMP), acquisition plan (AP), competition, prototyping, etc.]. BUDGETING — The process of translating resource requirements into a funding ACTIVITY — A task or measurable profile. amount of work to complete a job or part of a project. CRITICAL PATH METHOD (CPM) — A technique that aids understanding of the ACTUAL COST OF WORK PER- dependency of events in a project and the FORMED (ACWP) — The costs actually time required to complete them. Delayed incurred and recorded in accomplishing activities that have an impact on the total the work performed within a given time project schedule are critical and said to be period. on the critical path.

ARROW DIAGRAM METHOD (ADM) EARNED VALUE MANAGEMENT SYS- — A type of network diagram that labels TEM (EVMS) — An integrated manage- the activities on the lines connecting nodes. ment system that coordinates work scope, schedule, and cost goods and objectively BAR CHART — The detailed graphical measures progress toward these goals. It working plan of a part providing sequence is based on an industry-developed set of and time for the job scheduled ahead and 32 guidelines adopted for use by DoD in progress to date. 1999 for evaluation of contractor management systems. A complete listing of the BUDGETED COST OF WORK SCHED- guidelines is contained in DoD 5000.2-R, ULED (BCWS) — The sum of the budgets Appendix VI. for all work (work packages, planning pack- 79 FLOAT — The period of time that an activ- INTEGRATED PRODUCT TEAM (IPT) ity may be delayed without becoming a — Team composed of representatives from critical activity. Also known as slack or all appropriate functional disciplines work- path float/slack. ing together to build successful programs, identify and resolve issues, and make FREE FLOAT — The float that a single sound and timely recommendations to fa- activity can experience without affecting cilitate decision making. There are three any other activity. types of IPTs: overarching IPTs (OIPTs) focus on strategic guidance, program as- GANTT CHART — A graphic portrayal of sessment, and issue resolution; working a project which shows the activities to be IPTs (WIPTs) identify and resolve program completed and the time to complete repre- issues, determine program status, and seek sented by horizontal lines drawn in pro- opportunities for acquisition reform; and portion to the duration of the activity. Some program-level IPTs focus on program ex- Gantt charts will be able to show the float ecution and may include representatives for the activity. from both government and after contract award industry. INTEGRATED MASTER PLAN (IMP) — An event-based plan that depicts the over- LINE OF BALANCE (LOB) — A graphic all structure of the program and the key display of scheduled units versus actual processes, activities, and milestones. It de- units produced over a given set of critical fines the accomplishments and criteria for schedule control points on a particular day. each event in the plan. MASTER PROGRAM SCHEDULE INTEGRATED MASTER SCHEDULE (MPS)—The top-level schedule for the pro- (IMS) — The detailed task and timing of gram. It is prepared by the government the work effort in the IMP. A networked and includes all policy and contractual schedule that identifies all IMP events, events/activities. It is derived from the accomplishment, and criteria, and the ex- Program WBS and provides the baseline pected dates of each. for all subordinate schedules. It sometimes is called the program structure/ INTEGRATED PRODUCT AND PRO- schedule. CESS DEVELOPMENT (IPPD) — A management technique that simultaneously MILESTONE (MS) — The point when a integrates all essential acquisition activi- recommendation is made and approval ties through the use of multidisciplinary sought regarding starting or continuing teams to optimize the design, manufactur- (proceeding to next phase) an acquisition ing, and supportability processes. IPPD program. Milestones are: 0 [Approval to facilitates meeting cost and performance Conduct Concept Studies], I [Approval to objectives from product concept though Begin a New Acquisition Program], II [Ap- teamwork through Integrated Product proval to Enter Engineering & Manufac- Teams (IPTs). turing Development (EMD)], and III [Pro- duction or Fielding/Development and Operational Support (PF/DOS) approval]. A significant event that marks certain 80 progress, such as completion of a phase of RISK — A measure of the inability to the project. achieve program objectives within defined cost and schedule constraints. Risk is asso- MILESTONE CHART — A graphic ciated with all aspects of the program, e.g., portrayal of a program/project that shows threat, technology, design processes, work the events to be completed on a timeline. breakdown structure (WBS) elements, etc. It has two components: the probability of NETWORK SCHEDULE — A scheduling failing to achieve a particular outcome and technique that provides the means for de- the consequences of failing to achieve that fining task relationships and relationship outcome. lags. These may include such precedence relationships as “Start to Start,” “Finish to RISK MANAGEMENT — All plans and Finish," and "Start to Finish." actions taken to identify, assess, mitigate, and continuously track, control, and docu- PERT — See Program Evaluation Review ment program risks. Technique. SCHEDULE — Series of things to be done PERT Chart — A graphic portrayal of mile- in sequence of events within given period; stones, activities, and their dependency a timetable. upon other activities for completion and depiction of the critical path. SCHEDULE RISK — The risk that a program will not meet its acquisition strategy PRECEDENCE DIAGRAM METHOD — schedule objectives or major milestones A network diagram in which the activities established by the acquisition authority. are labeled in the nodes, usually boxes. SCHEDULE VARIANCE — A metric for PRODUCTION SCHEDULES — Chrono- the schedule performance of a program. It logical controls used by management to is the algebraic difference between earned regulate efficiently and economically the value (BCWP) and planned value (BCWS) operational sequences of production. (Variance = BCWP - BCWS). A positive value is a favorable condition while a PROGRAM EVALUATION REVIEW negaive value is unfavorable. TECHNIQUE (PERT) — A technique for management of a program from inception SCHEDULING — The prescribing of when through to completion by constructing a and where each operation necessary to the network model of integrated activities and manufacture of a product is to be per- events and periodically evaluating the formed. time/cost implications of progress. WORK BREAKDOWN STRUCTURE RESOURCE LEVELING — A process (WBS) — An organized method to break whereby resources are sorted out among down a project into logical subdivisions or tasks and activities to identify and avoid subprojects at lower and lower levels of conflicts between scheduling and avail- details. It is very useful in organizing a ability. project. See MIL-HDBK 881 for examples of WBSs. 81 82 APPENDIX D BIBLIOGRAPHY

Q. W. Fleming, J. W. Bronn, and G. C. Defense Systems Management College, Humphreys, Project and Production Schedul- Earned Value Management Textbook, DSMC, ing, Probus Publishing Co., Chicago, IL, Fort Belvoir, VA, April 16, 1998. 1987. Office of the Under Secretary of Defense H. Kerzner, Project Management: A Systems (Acquisition and Technology), DoD Inte- Approach to Planning, Scheduling, and Con- grated Product and Process Development Hand- trolling, Van Nostrand Reinhold, New York, book, DoD, Washington, DC, 1998. NY, 1998. D. T. Hulett, “Project Schedule Risk As- M. D. Rosenau, Jr., Successful Project Man- sessment,” Project Management Journal, agement: A Step-by-Step Approach With Prac- March 1995. tical Examples (2nd Edition), Van Nostrand Reinhold, New York, NY, 1992. PMI Standards Committee, A Guide to the Project Management Body of Knowledge, D. C. Cleland, Field Guide to Project Manage- Project Management Institute, Newton ment, Van Nostrand Reinhold, New York, Square, PA, 1996. NY, 1998. J. R. Knutson, How To Be A Successful Project J. J. Mayer, Time Management for Dummies Manager, IEEE Successful Management (2nd edition), IDG Books Worldwide, Inc., Series, Undated. Foster City, CA, 1999. J.P. Lewis, Project Planning, Scheduling & Defense Systems Management College, Control, McGraw-Hill, New York, NY, 1995. Acquisition Strategy Guide, DSMC, Fort Belvoir, VA, 1998.

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