It has been traditional in the construction industry to employ an architect/engineer (A/E) to complete a detailed design of the entire project before soliciting bids from construction contractors. This traditional approach is known as sequential design and construction. This sequential design/construction approach requires that a detailed design package of the entire project be complete before bids are solicited from construction contractors. Following award of the construction contract, the A/E is often retained by the owner for the construction phase, and acts as the owner’s agent, to inspect the construction work to ensure that the structures are built according to the designs and specifications.

Advantages – A major advantage of the sequential design and construction approach is that complex or one- of- a- kind projects can be thoroughly planned and thought through before construction begins. The traditional approach thus produces, in the design phase of the project, the most accurate estimate of final project costs, and this is an advantage of the traditional technique. If problems are encountered with design aspects for the latter stages of the project, the earlier design features or phases can be modified before any construction work has been done, thus avoiding construction contractor claims and delays.

Another advantage is that the Agency is given a fixed price for completion of the entire project before construction begins. There may also be advantages in obtaining the necessary financing and project approvals. Overall management of the project should also be simplified by this approach.

Disadvantages – Sequential design and construction requires a longer time to complete the project than phased design and construction (“fast tracking”). And since time pressures are often the most intense issues confronting the Agency, the sequential method may not be feasible. Alternative contracting approaches have arisen to shorten the project completion time. These include phased design and construction (“fast tracking”), which often involves the use of a construction manager, and turnkey (design-build) contracting.

A Noncompetitive Procurement Justification and the Sole Source Cost Analysis must be completed and submitted for inclusion in the project master file prior to proceeding with this
type of procurement.