Cost Analysis Metrics The cost analysis identified that transit station projects exhibit the highest amount of increase in construction costs of any project that the MBTA performs. Other types of projects performed by the MBTA include bridges, commuter rail upgrades, maintenance facilities, etc. On average, transit station construction exhibited a 24.67% increase in cost, ranging from a low of 5.09% to a high of 73.45%. Schedule Analysis Metrics The schedule analysis identified that transit station projects, on average, exhibit schedule growth impacts of 80.36%, much more than any other type of project performed by the MBTA. Ranging from a low of -0.34% to a high of a 324% increase in planned schedule performance was calculated. Major Drivers for Cost and Schedule Growth The major reasons for the increase in project cost and schedule delays resulted from: Budget considerations Additions / Modifications to Project Scope Differing Site Conditions Work in stations open for operations MBTA driven changes Budget Considerations Oftentimes, project funding is not available to completely address the total scope of work required to renovate the station. As a result, the station renovation is performed in phases, with work performed by different contractors. Performing work in this manner results in extended construction durations due to having to put out multiple contracts, and higher overall costs due to the time value of money. An example of this is Ashmont Station. Due to funding issues, the station renovation was segmented with the initial contract providing a basic accessible station, followed by a station finishes contract. Additions / Modifications to Project Scope During the execution of the construction contract, additional scope elements are frequently requested and provided. Added scope elements can originate from a number of sources, and usually have an impact on costs and overall schedule duration. Contracts that have had significant additions/modifications to project scope are Kenmore, State, Arlington, Copley, Ashmont, and Maverick. Differing Site Conditions
Cost Analysis Metrics The cost analysis identified that transit station projects exhibit the highest amount of increase in construction costs of any project that the MBTA performs. Other types of projects performed by the MBTA include bridges, commuter rail upgrades, maintenance facilities, etc. On average, transit station construction exhibited a 24.67% increase in cost, ranging from a low of 5.09% to a high of 73.45%. Schedule Analysis Metrics The schedule analysis identified that transit station projects, on average, exhibit schedule growth impacts of 80.36%, much more than any other type of project performed by the MBTA. Ranging from a low of -0.34% to a high of a 324% increase in planned schedule performance was calculated. Major Drivers for Cost and Schedule Growth The major reasons for the increase in project cost and schedule delays resulted from: Budget considerations Additions / Modifications to Project Scope Differing Site Conditions Work in stations open for operations MBTA driven changes Budget Considerations Oftentimes, project funding is not available to completely address the total scope of work required to renovate the station. As a result, the station renovation is performed in phases, with work performed by different contractors. Performing work in this manner results in extended construction durations due to having to put out multiple contracts, and higher overall costs due to the time value of money. An example of this is Ashmont Station. Due to funding issues, the station renovation was segmented with the initial contract providing a basic accessible station, followed by a station finishes contract. Additions / Modifications to Project Scope During the execution of the construction contract, additional scope elements are frequently requested and provided. Added scope elements can originate from a number of sources, and usually have an impact on costs and overall schedule duration. Contracts that have had significant additions/modifications to project scope are Kenmore, State, Arlington, Copley, Ashmont, and Maverick. Differing Site Conditions