System Wide Station Security Improvement – Green Line Construction Contract Time Determination (Ctd)
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MBTA Contract No. S99PS04 SYSTEM WIDE STATION SECURITY IMPROVEMENT GREEN LINE MASSACHUSETTS SYSTEM WIDE STATION SECURITY IMPROVEMENT – GREEN LINE CONSTRUCTION CONTRACT TIME DETERMINATION (CTD) Prepared for: February 17, 2021 Prepared by Amir Khalafi HNTB Corporation MBTA SYSTEM WIDE STATION SECURITY IMPROVEMENT BD CTD TABLE OF CONTENTS 1. PREFACE ................................................................................................................................................ 3 2. SUMMARY ............................................................................................................................................. 3 3. REFERENCE ............................................................................................................................................ 4 4. METHODOLOGY .................................................................................................................................... 4 5. WORK BREAKDOWN STRUCTURE ......................................................................................................... 5 6. BASIS & ASSUMPTIONS & RISKS ........................................................................................................... 5 7. CRITICAL PATH ...................................................................................................................................... 6 8. CALENDARS ........................................................................................................................................... 6 9. ATTACHMENTS ...................................................................................................................................... 7 2 MBTA SYSTEM WIDE STATION SECURITY IMPROVEMENT BD CTD 1. PREFACE HNTB has produced a Contract Time Determination (CTD) study for the procurement and installation of the communications and security scope of the Green Line Security Improvements project. The CTD was developed to provide validation of the overall conceptual duration of the project and to identify the work items that are critical for timely completion using the Critical Path Method (CPM) scheduling technique. The construction sequence shown in this CTD is based on Bid Package submittals and discussions with MBTA that determined calendar restrictions and sequence of work. Note that this CTD is based on a specific suggested construction approach that successfully completes the work described in the design documents. The CTD is included in Attachment A. 2. SUMMARY The CTD concludes that an adequate construction duration to complete the project from Notice to Proceed (NTP) to Project Substantial Completion is 257 calendar days (approximately eight and a half months) and from Notice to Proceed (NTP) to Project Final Completion is 287 calendar days (approximately nine and a half months). This duration is based on the following milestones: 3 MBTA SYSTEM WIDE STATION SECURITY IMPROVEMENT BD CTD 3. REFERENCE The schedule was developed using the information contained in the following documents: • Green Line Security Improvements BD Submittals 4. METHODOLOGY The schedule was prepared using Critical Path Method (CPM) scheduling techniques to estimate the conceptual project duration. Primavera P6 Professional (P6-V18) was used to develop the CPM schedule. The overall scope of work was identified and analyzed based on the information from plans and specifications. The project scope was further broken down into a discrete Work Breakdown Structure (WBS) and unique items of work (activities). See Section 5, “Work Breakdown Structure WBS” for detail. The duration of activities was then analyzed based on production rates, and relevant calendars were assigned. After defining the activities, logical relationships and interdependencies between the activities were created to reflect the suggested sequence in which work will be performed. The schedule was then calculated to determine the overall conceptual project duration based on the activity durations and logical sequence of the activities. Note that this schedule represents one approach to completing this section of the project. During the construction phase of this project, the Contractor may present an alternative approach to construction that alters the order of activities and modifies the schedule. This schedule does not limit the Contractor’s means and methods. 4 MBTA SYSTEM WIDE STATION SECURITY IMPROVEMENT BD CTD 5. WORK BREAKDOWN STRUCTURE The WBS was developed as a functional breakdown of the project scope based on geographical position as well as work type. The top section of the schedule presents summary of work. Shown below is a sample representation of the WBS: 6. BASIS & ASSUMPTIONS & RISKS The construction durations in the Contract Time Determination Schedule (CTD) are based on information generated in the Green Line Security Improvements 100% submittals. • Construction work to be continuous and uninterrupted. • The schedule assumes no resources constraints. Adequate skilled labor is locally available as well as equipment and materials. • The schedule assumes two crews work simultaneously, one starting at Arlington station and the other at Prudential station. • The schedule assumes activities “Emergency Intercom/Phones,” “Access Control,” and “CCTV” will start when 50% of “Conduit & Cable Installation” is completed at each station (Use SS relationship with positive lags). 5 MBTA SYSTEM WIDE STATION SECURITY IMPROVEMENT BD CTD 7. CRITICAL PATH The project critical path is the longest continuous path of activities throughout the project. The critical path determines the completion date of the project. A delay in any of the activities on the critical path will delay the completion date of the project. The Longest Path begins with NTP on Apr 01, 2021. This is followed by project submittals and procurement activities. • Stations Starting with Boylston and Prudential stations, the Critical Path is followed by “Conduit & Cable Installation” activities. Critical path work continues with activities of Copley, Arlington and Riverside stations. Project substantial completion is achieved on Dec 14, 2021. • Project Closeout Final Completion occurs on Jan 13, 2022. 8. CALENDARS The SSSI Contract Time Determination (CTD) Schedules utilizes two (2) project- specific calendars. Listed below is each calendar with a brief description. • MBTA – SSSI – 5D/8H W/H – This calendar utilizes a five (5) day (Monday, Tuesday, Wednesday, Thursday, Friday), eight (8) hour workweek. It is expected that the eight-hour shift occurs between 8 AM and 4 PM unless otherwise approved by MBTA. This calendar excludes work on six (6) holidays (New Year’s Day, Memorial Day, 4th of July, Labor Day, Thanksgiving Week, and Christmas Day) per year. No work during the week of Thanksgiving. 6 MBTA SYSTEM WIDE STATION SECURITY IMPROVEMENT BD CTD • MBTA - 7 DAY – NO HOL – This calendar was used for submittals and procurement. 9. ATTACHMENTS A. CTD – WBS LAYOUT 7 MBTA SYSTEM WIDE STATION SECURITY IMPROVEMENT BD CTD ATTACHMENT A 8 Activity ID Activity Name OD Start Finish 2021 2022 Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug MBTA SYSTEM WIDE STATION SECURITY IMPROVEMENTS - GREENLINE - BD198d CTD01-Apr-21 - 0217202113-Jan-22 13-Jan-22, MBTA SYSTEM WIDE STATION SECURITY IMPROVEMENTS - GREENLINE - BD CTD - 02172021 Contract Milestones 288d 01-Apr-21 13-Jan-22 13-Jan-22, Contract Milestones SSSI-G-1000 NTP Construction Contract 0d 01-Apr-21 NTP Construction Contract SSSI-G-1010 Project Substantial Completion 0d 14-Dec-21 Project Substantial Completion SSSI-G-1020 Project Final Completion 0d 13-Jan-22 Project Final Completion Pre-Construction 40d 01-Apr-21 27-May-21 27-May-21, Pre-Construction SSSI-P-1030 Project Submittals 20d 01-Apr-21 28-Apr-21 Project Submittals SSSI-P-1040 Review & Approve Project Submittals 20d 29-Apr-21 27-May-21 Review & Approve Project Submittals SSSI-P-1050 Material Procurement 20d 29-Apr-21 27-May-21 Material Procurement Construction 138d 28-May-21 14-Dec-21 14-Dec-21, Construction BOYLSTON STATION 38d 28-May-21 21-Jul-21 21-Jul-21, BOYLSTON STATION SSSI-C-1145 Equipment Staging - BOYLSTON STATION 1d 28-May-21 28-May-21 Equipment Staging - BOYLSTON STATION SSSI-C-1150 Conduit & Cable Installation - BOYLSTON STATION 18d 31-May-21 23-Jun-21 Conduit & Cable Installation - BOYLSTON STATION SSSI-C-1160 Network Switches Installation - BOYLSTON STATION 1d 28-May-21 28-May-21 Network Switches Installation - BOYLSTON STATION SSSI-C-1170 Integrate Network Devices to Existing Network - BOYLSTON STATION 2d 31-May-21 01-Jun-21 Integrate Network Devices to Existing Network - BOYLSTON STATION SSSI-C-1180 Emergency Intercom/Phones - BOYLSTON STATION 1d 14-Jun-21 14-Jun-21 Emergency Intercom/Phones - BOYLSTON STATION SSSI-C-1190 Access Control - BOYLSTON STATION 6d 15-Jun-21 22-Jun-21 Access Control - BOYLSTON STATION SSSI-C-1200 CCTV - BOYLSTON STATION 10d 23-Jun-21 07-Jul-21 CCTV - BOYLSTON STATION SSSI-C-1210 System Testing and Misc - BOYLSTON STATION 5d 08-Jul-21 14-Jul-21 System Testing and Misc - BOYLSTON STATION SSSI-C-1220 Close Out (Burn-in + Commisioning) - BOYLSTON STATION 5d 15-Jul-21 21-Jul-21 Close Out (Burn-in + Commisioning) - BOYLSTON STATION COPLEY STATION 63d 15-Jul-21 13-Oct-21 13-Oct-21, COPLEY STATION SSSI-C-1225 Equipment Staging - COPLEY STATION 1d 15-Jul-21 15-Jul-21 Equipment Staging - COPLEY STATION SSSI-C-1227 Furnish & Prep the Com Room - COPLEY STATION 2d 16-Jul-21 19-Jul-21 Furnish & Prep the Com Room - COPLEY STATION SSSI-C-1230 Conduit &