Concurrent Delay Analysis: Part 1
By: Charles Choyce
Few topics in schedule delay analysis generate more interest than concurrent delay. This will be the first in a series of blogs on this important issue in analyzing construction delay claims. In this blog, we will discuss the general meaning of concurrent delay.
Although one case decided by the Federal Claims Court stated, “an exact definition of concurrent delay is not readily apparent,” the concept of “concurrent delay” is usually understood to mean that where both parties contribute to a delay in the completion of a construction project during the same period of time, the contractor is entitled to a time extension but no compensation for the concurrent delay. By the same token, where concurrent delay is established, the owner may not withhold liquidated damages or recover delay damages for delays caused by the contractor.
The classic concept of concurrent delay is shown in Illustration 1, where two simultaneous delay events—one the responsibility of the owner and the other the responsibility of the contractor—independently cause an equal delay to the completion of the project on a single critical path.
Another common concurrent delay situation occurs when there are two concurrent critical paths: the owner delays one path at the same time that the contractor delays the other path, for exactly the same duration (Illustration 2).
A final situation may or may not be a concurrent delay. Where there is a single critical path, and during the same general time period (such as a month between schedule updates), there is first a delay by one party to the critical path, followed by a delay by the other party (Illustration 3). The question arises whether the delay should be apportioned between the parties, in which case the owner would pay compensation for the owner portion of the delay, and the contractor would pay liquidated damages for its delays; or whether the delay during that time period is a concurrent delay, with no compensation to either party. For example, the owner may make design changes that delay the release of steel for fabrication, followed by a contractor delay in steel fabrication because of an equipment breakdown at the fabricator. This might be viewed as concurrent since the equal delay impacts occurred during the same month. However, several court decisions state that such delays should be apportioned to each party.
While the above concepts are generally understood, in reality it is not surprising that the owner and contractor delays normally do not align in perfect equality. That is where the issue of concurrent delay can become can become quite fact specific.
In the next part of this series, we will discuss approaches to analyzing whether delays are concurrent.
 George Sollitt Constr. Co. v. United States, No. 99-979C (Fed.Cl. 2005), p. 7, n.8.
The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of Berkeley Research Group, LLC.