It is safe to assume that contractors have been asserting delay claims or their effective equivalents on projects since before the start of recorded history. While we have no record of delay claims on the Pyramids, I am sure that King Djoser’s architect Imhotep, hoped the funerary pyramid he designed would be completed prior to, or at least near to the time of death of the king in 2670 BCE, even though it took dozens of years to complete. Similarly, we do know that in medieval times the popes who built the Duomo in Florence and St. Peters Basilica in Rome complained to their master-builders Brunelleschi and Michelangelo about the very long time and the cost overruns these projects had on the way to completion. Much more recently, U.S. courts have reported delay claims for more than 100 years.
Since the mid-20th century and the advent of critical path method (CPM) scheduling, that invention has not only revolutionized both the planning and execution of construction projects, but also the claims for delays asserted by contractors. These claims are different than their predecessors only in the potential for “scientific” proof of delay. CPM schedules came into existence in the late 1950s with the development of the UNIVAC computer and the work of J. Mauchly and J. Kelley on behalf of DuPont. Those initial trials of this schedule system proved almost immediately that CPM schedule development could save considerable time. Shortly thereafter, the Navy’s Polaris Program developed a statistical tool called the project evaluation and review technique (PERT). So that by the end of the 1960s, CPM scheduling fundamentals were essentially in place, albeit working on computers we would consider unbearably slow today.
In the mid-1960s some schedule experts started to identify and quantify delays through the use of “time-impact analysis” (TIA) and snapshots of time. As the Apollo moon project advanced, experts working with the CPM schedules used time-impact analysis methods to quantify and project time delays that occurred on the project. As CPM usage became more prevalent, the number of different forensic schedule delay methods seems to have grown rapidly, with some current commentators having identified up to 14 different methods, (R. D’Onofrio and A. Meagher, What is a Schedule Good For? A Study of Issues Posed by Schedules on Complex Projects, ABA Constr. Law., (Winter 2013)) while others aggregate the subtle differences into four major families. (P. Levin, ed., Construction Claims, Changes, and Dispute Resolution, 3rd Ed., Chapter 8 (ASCE Press, 2016))
While delays occur on all projects, constructors and owners work diligently to avoid delays, and if they occur, to recover from them. Most of the time, their efforts are successful and therefore few projects have critical path schedule delays and even fewer have claims that result from requests for additional time. Nevertheless, when such claims do occur, they can be complicated and ironically, time consuming. For this reason, time is an essential element of all construction projects, and construction professionals should all be aware of the principal issues associated with extensions of time and delay claims.