Numerous studies have examined the use of various
delivery methods in the transportation sector, most notably design-bid-build
(DBB), design-build (DB), and construction manager/general contractor
(CM/GC). However, the influence of these
methods on agency resources has not been studied in depth. More specifically, there has not been a
quantifiable estimate of how different delivery methods affect total project
costs incurred by agencies throughout the project delivery cycle. Thus, owner
agencies with limited resources may not have clarity on how to demonstrate
value for money in the delivery method selection process. For the purposes of
this statement, total costs incurred by an agency through the project life
cycle minus direct project costs paid to the general contractor are referred to
as agency costs.
Numerous studies have examined the performance
implications of using various delivery methods, including the cost
implications. However, cost analyses tend to focus on direct project costs only
and not include the internal costs to the agency of managing the project. Other studies acknowledge that different
delivery methods will require varying levels of involvement by the owner. Yet
these studies tend to describe levels of involvement in generalities without
quantification. Therefore, a cost analysis to include agency costs will prove
useful to agencies in their delivery method decision process.
A previous case study of two nearly identical bridge
replacement projects showed a difference in both direct project cost and agency
cost, with one project being delivered via DBB and the other DB by Washington
DOT. This case study provides a starting
point, but cannot be generalized to other projects or states. A more
comprehensive analysis is needed to draw firm conclusions related to agency
Other projects have examined the agency costs of
various facets of the project process, but not by delivery method. For example, NCHRP Report 826: Estimating
Highway Preconstruction Services Costs examined agency costs related to
preconstruction services, including services offered by agency staff. Such projects provide background on how to
examine agency costs, and should help inform the current proposed project.
proposed research project should address the following questions:
do agency costs vary under the use of different delivery methods?
do agency costs vary by phase of the project under different delivery methods,
e.g. planning, design, pre-award, and post-award phases?
do total project costs (agency costs + direct project costs) vary under the use
of different delivery methods?
are the appropriate procedures to estimate agency costs?
can delivery methods be selected to maximize value money?
should agency costs be incorporated as a factor into other delivery method
decision making frameworks?