Construction claims involve the recovery of damages.  Since time is money, issues concerning time are generally involved in most construction claims.  Contractors must provide factual support and credible evidence to assist in calculating delay, time extensions, concurrency, liquidated damages and actual damages.  There are different methods of scheduling analysis, some more reliable than others.  In a recent article, a series of “best practices” were suggested that should improve the reliability of construction scheduling evidence and increase its acceptability.[1]  This blog is a synopsis of that article. Though there are likely dozens of variations of individual critical path method (“CPM”) schedule delay analyses, they generally fall within the genre of the five following methods:

1.  Time Impact Analysis: Time Impact Analysis (“TIA”) utilizes the change to the projected completion between the contemporaneous schedule updates to evaluate critical delays during the project in a chronological and cumulative fashion.

2.  Collapsed As-Built:  Collapsed As-Built (“CAB”) methods remove specific delay from the as-built schedule to show where the contractor would have finished, but for that delay.

3.  As-Built Critical Path: As-Built Critical Path (“ACP”) methods identify delays that fall on the longest path in the as-built schedule. 

4.  Impacted As-Planned: Impacted As-Planned (“IAP”) methods project delays into the baseline schedule as if they had been known at the start of the project.

5.  Total Time (As-Planned vs. As-Built):  Total Time (“TT”) method compares the original As-Planned schedule with the As-Built schedule and considers the difference extensions of time. 

Many of these methods have been criticized in legal decisions depending on how they were used, their completeness and accuracy.  The problem with these methods is that they can produce different results when applied to the same fact scenarios. 

The general consensus noted by most practitioners is that the Time Impact Analysis is the preferred method among these five genres.  Confusing is the fact that frequently consultants and experts refer to the method they use as the “Time Impact Analysis” regardless of what actual method they actually use.  Some experts argue that all five methods are acceptable in certain situations, even the acknowledged flawed Collapsed As-Built and the As-Built Critical Path methods.  Instances where the Time Impact Analysis, which requires schedule updates, cannot be used because no updates were conducted during the project.  Some schedules resort to a less reliable method to perform the delay analysis.  The failure to comply with the contractual provision for schedule updates may in and of itself preclude the contractor from recovery.

To bring some clarity to these schedule delay analyses the authors proposed eight “best practices guidelines” with which any schedule delay analysis should comply:

1.  Compare the plan to perform the remaining work before each delay with the plan to perform the remaining work after that delay;

2.  Identify critical delays;

3.  Evaluate all the delays in a chronological and cumulative manner;

4.   Adjust the contract completion date to reflect the excusable delay as it occurs;

5.  Include accurate as-built information in the analysis;

6.  Minimize projected future delays;

7.  Correct any necessary logic flaws, but carefully document and explain any changes to contemporaneous schedules; and

8.  Tie causation to each delay in accordance with the principles of schedule delay.

These eight simplified guidelines reflect the checklist that a contractor, court, arbitration tribunal or dispute resolution board can use to assist in identifying the accuracy and the reliability of the schedule analysis method. 


[1] Gavin & D’Onofrio, Scheduling (Programme) Analysis: Hired Gun Advocacy for Effectively Meeting a Burden of Proof? Construction Law International, Vol. 7, Issue 3, October 2012.

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