Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1-1-2000 Theory of Constraints compared to a case study of interior design project development scheduling Ajith Basu Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Recommended Citation Basu, Ajith, "Theory of Constraints compared to a case study of interior design project development scheduling" (2000). Retrospective Theses and Dissertations. 21068. https://lib.dr.iastate.edu/rtd/21068 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Theory of Constraints compared to a case study of interior design project development scheduling by AjithBasu A thesis submitted to the graduate faculty in partial fulfillm.ent of the requirements for the degree of MASTER OF ARTS Major: Art and Design (Interior Design) Major Professor: Shirlee Singer Iowa State University Ames,Iowa 2000 ii Graduate College Iowa State University This is to certify that the Master's thesis of Ajith Kumar Basu has met the thesis requirements of Iowa State University Signatures have been redacted for privacy iii Dedicated To The Creative Genius ..• iv TABLE OF CONTENTS LIST OF FIGURES V LIST OF TABLES vi LIST OF ABBREVIATIONS vii ACKNOWLEDGEMENTS viii CHAPTER 1. INTRODUCTION 1 CHAPTER 2. THEORY BASE OF THE STUDY 7 CHAPTER 3. RESEARCH DESIGN 25 CHAPTER 4. DATA COLLECTION AND RECORDING 39 CHAPTER 5. DATA ANALYSIS 57 CHAPTER 6. CONCLUSION 71 APPENDIX 81 BIBLIOGRAPHY 82 V LIST OF FIGURES Figure 1. Inductive Mode of Research in Qualitative Study 26 Figure 2. Research Design Roadmap 27 Figure 3. Plan of the Commercial Construction Unit (CC UNIT-I & CC UNIT-II) 28 Figure 4. View of the Commercial Construction Unit (CC UNIT-I & CC UNIT-II) 29 Figure 5. Parts of the Commercial Construction Unit (CC UNIT-I & CC UNIT-II) 30 Figure 6. Preliminary Schedule of the Commercial Construction Unit-I (CC UNIT-I) 32 Figure 7. Preliminary Schedule of the Commercial Construction Unit-II (CC UNIT-II) 33 Figure 8. Combined Detailed Schedule of Commercial Construction Units-I & II (Process Unit 1.) 34 Figure 9. TOC Schedule of the Commercial Construction Units-I & II (Process Unit 2) 35 Figure 10. Project Development Resources 41 Figure 11. Preliminary Flow Chart of the Project Development Process 42 Figure 12. Detailed Flow Chart 44 Figure 13. Combined CPM Schedule of Commercial Units - I & II 66 vi LIST OF TABLES Table 1. Calculation of Expected Activity Times (TE) and Variances ofCCUNITI 64 Table 2. Calculation of Expected Activity Times (TE) and Variances of CC UNIT II . 65 vii LIST OF ABBREVIATIONS appro. Approval CD Construction Documents CIM Computer-Integrated Manufacturing elec. Electrical eqpt. Equipment R Resource TOC Theory of Constraints viii ACKNOWLEDGEMENTS By the time, I completed the thesis I had the satisfaction of working with an excellent group of creative individuals. The group consisted of my major professor Prof. Shirlee Singer who helped me coordinate the entire research and writing effort. She occasionally took the time to learn what is new in the field and guided me into it. Prof. Barb Flynn, a management professor, with her management wisdom, supported all the management aspects of the study. She played a key role in my choosing the case study as the procedure. Prof. Bruce Bassler, a professor and practitioner of Architecture, guided me through some aspects of professional practice that formed an essential background for my study. My editor Deborah Miller helped guide the flow of the language while patiently working with me. The efforts of this group would never have been complete without the support of my beloved wife Usha and our parents. 1 CHAPTER 1. INTRODUCTION This study explores the advantages of the of the project management application of Theory of Constraints {TOC) on the project development of commercial rollout units and thus generalizes the advantage of this implementation to other interior design projects. Specifically, this study examines whether TOC scheduling techniques can be applied to the design development phase of commercial rollout units to reduce the project development lead time and in turn creates an inference on its application in reducing the overall lead time of interior design projects. Project development lead time is defined here as the lag time between receiving the initial project background data and transferring the processed data to the manufacturing team. Overall project lead time is defined as the time elapsed between collecting initial background design data to completing the manufacturing. Commercial rollout units defined here are multiple kiosk units with the same overall design, finish, and components. The Problem Statement As profit is directly related to overall project lead tjme and meeting the deadline, project managers are always under pressure to reduce lead time in different phases of interior design projects. Saving project lead time and meeting the deadline is the key decisive factor in the generation of profit in a project. Similarly, any saving in the project lead time and meeting the deadline will enhance the profit created in the development phase of the project. A project schedule represents the timeline of the project phase, indicating the start to finish of each task, the overall lead time, and deadline. Over the years project managers, to 2 plan and control different phases of interior design projects, have used many project scheduling systems. Studies on project scheduling so far indicate that a project planner cannot choose a single system of scheduling as a standard. Endeavors by design companies to make a single scheduling system as their standard have failed. In fact, design companies choose project scheduling approaches based on the size and complexity of a project (Burstein, David, and Frank Stasiowski, 1991). The scheduling technique created, based on the management theory, Theory of Constraints (TOC) claims effectiveness in managing the lead time and thus, increasing project profit. However, to my knowledge, it has never been tried in the project development phase of interior design. Since it has proved successful in other fields such as manufacturing, it may be an effective scheduling tool for interior design project development. Today's project planner is concerned with three important objectives while creating a project schedule. The first objective is to make the project meet the cost, the second objective is to make the project meet the quality standards of the client, and the third is to meet the project deadline (Horsley, 1991). Theory of Constraints states that, time is the major factor in project scheduling since it can control the profit (Avraham Y. Goldratt Institute, 1994). TOC claims, by its scheduling technique, that it can reduce project lead time while ensuring quality. The "Theory ofConstraints" was developed by the Avraham Y. Goldratt Institute in the 1980s. While developing a common sense methodological approach to problems and improvements associated with global business, the institute developed a series of TOC application areas such as project management, distribution, marketing and sales, production and the direction of the company (Avraham Y. Goldratt Institute, 1994). Theory of 3 Constraints (TOC) suggests a reform in the field of project management by stating that there . is a need to address a new type of constraints within the project management process, which has not been addressed before by traditional scheduling methods. While comparing the TOC scheduling method with the traditional scheduling methods, the Goldratt Institute points out three areas of weakness that exist in the latter. Based on this comparison we ca,n assume several generalizations about our knowledge concerning interior design project development scheduling. First, project managers tend to lose focus during the project irrespective of the fact that the project has an early start or a late start. A proper control mechanism, which is not addressed by traditional techniques, can keep the focus intact (Goldratt, 1997). No studies related to an interior design project development schedule were found which addresses the comparison based on this aspect. Second, are the practices followed by project managers to add and manage safety time. (Safety time is the extra time added to the time of a task or overall project lead time to take care of the unexpected waste of time and delay.) Theory of Constraints indicates that project managers, due to mismanagement of safety time, neither achieve a realistic lead time nor reach the goal of actual profit. Mismanagement of safety time creates the phenomenon of unpredictable lead time. To conclude, the aspect of safety time management is overlooked by past scheduling methods and studies. The theory also indicates that the assumptions used for the proper calculation, addition, and usage of safety time is also inadequate (Goldratt, 1997). No studies were found which attempted to examine the importance of properly managing the safety time in an interior design project development schedule. 4 Third, the project schedules using traditional methods are created using cost world assumptions, whereas the project schedules using TOC are created based on throughput world assumptions. Cost world assumptions are the management assumptions based on traditional cost accounting and the throughput world assumptions are based on the management assumptions of TOC. In the Theory of Constraints "throughput" is defined as the rate at which a system makes money through sales. No studies were found to explore the difference in project scheduling using these two assumptions in the context of interior design project development schedule. Thus for interior design project managers, the question is, whether the use of TOC scheduling methods is advantageous over the traditional scheduling methods including barchart and CPM.