One of the most problematic issues relating to construction delay claims is that of concurrency.  Indeed, concurrency causes problems for many of those involved with construction claims, not only contract administrators (e.g., architects and engineers), but also for claims consultants, experts, lawyers and, apparently, even some members of the judiciary.[1]  This article seeks to discuss the issue of concurrency in both an international and regional setting.[2]

The problems stem partly from the fact that there appears to be no agreed definition of what is meant by concurrency or how it should be interpreted and applied. Other problems arise when trying to determine whether concurrency applies to simultaneous or sequential[3] events and whether it is the event or its effect which is important. 

The above problems are not helped by the lack of a single, definitive authority which deals with all of the above, and these problems are further compounded by a difference of approach in different legal jurisdictions.[4] 

What is concurrency?