Disfavored Schedule Delay Analysis Methods

Warning – Owners and contractors should not perform a delay analysis without the help of an expert in the field!

The following summary assessments of disfavored schedule delay analysis methods are based on Holloway Consulting’s 40+ years of contemporaneous and retrospective construction project schedule delay analysis. However, they should not be construed as expert opinions.


The Army Corps’ of Engineers Modification Impact Evaluation Guide (EP-415-1-3) is known in construction consulting and construction expert circles as a technique used for the contemporaneous evaluation of schedule delays. This technique has also been used in labor productivity analyses, and shares similarities with the Time Impact Analysis technique discussed below. We have rarely seen EP-415-1-3 used in private contract disputes, which may be attributable to the rigors of the technique and its attendant costs. We have seen it used only once in retrospective analysis, and most construction schedule delay experts agree that it should be used contemporaneously or not at all.


The Impacted As-planned Schedule Analysis was popular in the 1960s, 70s, and 80s in CPM construction schedule delay and acceleration claims. In this analysis, delays are developed as unique activities, and inserted into the (un-progressed) contract, baseline, or reasonable as-planned schedule. A schedule calculation is then performed and a new “adjusted” completion date is established. The hypothetical impact of delays on the completion of the work is then portrayed through a comparison of either the original as-planned completion date or the actual completion date, and the new, adjusted completion date.

The growing consensus in today’s legal community is that the impacted as-planned schedule is not an appropriate basis for quantifying project delays, particularly when this technique is used in an attempt to establish the date the contractor finished its work. Numerous court and board of contract appeals decisions indicate that attempts to quantify delay days through the usage of as-planned impacted CPM analyses are unlikely to be accepted. Decisions that address the as-planned impacted schedule analysis in delay claims include Gulf Contracting, Inc., Titan Pacific Construction, and Ealahan Electric Co.

Two obvious weaknesses in using the Impacted As-planned Schedule analysis to prove delay are that it (1) omits the as-built history of the job and (2) ignores the fact that the critical path(s) will often change as work progresses and schedules change.

On the other hand, in certain comparative negligence situations, the as-planned impacted technique is a preferred technique employed to apportion each party’s (owner, designer, contractor, etc.) share of the overall impact to the contractor’s cost overruns due to lost craft labor productivity. This technique has been accepted in situations where the actions of the owner, designer(s) and/or contractor(s) have adversely affected the project, and where comparative analysis is needed to provide a reasonable measure or allocation of each party’s impact to the contractor’s direct labor cost overruns.


Another decreasingly popular approach to demonstrating impact on construction schedules is the Global Impact Method. Although simplistic and easy to present, it is an inaccurate method of demonstrating the impact of delay-causing events. Using this method, delays, disruptions, and similar occurrences are outlined in a narrative text. The start and end dates are determined for each event and the duration of each delaying event is computed.

The alleged duration of the delay is often an arbitrary assignment which may not have had any effect upon the project completion date. For example, the approval of a hardware schedule may take three weeks longer than stipulated in the contract, but the procurement of the item will only take two weeks and it is not needed on site for months. The total delay to the project is purported to be the sum total of the durations of all delaying events, even though there was concurrency, or overlap, and perhaps no delay to the completion date.

Use of this technique is almost certain to be met with some type of motion from the other side.


In an apparent attempt to avoid concurrent schedule delay issues, claimants sometimes employ the Net Schedule Impact Method technique in an effort to depict the net effect of all claimed delays. Claimants will often allege that the compensable delay period equals the difference between the contract completion date and the actual completion of the work and the substantial completion date.

In this analysis, delays, disruptions, and work suspensions are typically plotted on an as-built schedule. Change Order Requests/Change Orders are commonly depicted as delays, and every change is alleged to have impacted project completion. With extensive delaying events displayed on the as-built schedule, but without any network calculations, the claimant will argue that combined effect of the events has delayed the project.

Such an analysis is perhaps better suited for delay and disruption claims, although we are currently unaware of any consensus amongst experts on this point.


Another method of impacting the as-built schedule is to develop the construction schedule in CPM format with activity relationships. The critical path is determined twice – once in the as-planned schedule and again at the end of the project. Claimants invariably tie delaying events that are the responsibility of the other party to the critical path.

This method is similar to the impacted as-planned analysis. However, the starting point is the final as-built schedule rather than the initial as-planned schedule. Thus, the proponents of this method argue that it is based upon actual progress history. However, the calculation of the critical path tends to be somewhat contrived for two reasons. First, it is an after-the-fact calculation. (CPM scheduling is a forward-looking management tool that projects the future based in part on past performance.) Second, the calculation is made only twice-at the start and the end of the job. It would be more appropriate to calculate the critical path on an incremental basis at the time the delay occurred because the critical path of a schedule often changes throughout the course of construction.

When a claimant uses this schedule technique, one may question the veracity of the alleged critical path. In this sense, this technique is not much better than the net impact technique. The two techniques are similar in that the claimant will often acknowledge its own delays by depicting them on the as-built schedule in such a way as to reflect that they were not critical or in a manner that minimizes their impact. But no attempt is made to isolate the individual impact of each delay on the project completion.


What are the primary characteristics that differentiate favored techniques from those less favored? – Industry standards, case authority, contract clauses, agency manuals, government regulations and expert opinion emphasize the use and analysis of updates to the schedule at specific data dates, or reference points, during the project to assess gains and losses on the critical path(s) and near-critical path(s) of the schedule. Whether prepared contemporaneously or retrospectively, such analyses should start at the beginning of the project with the contract or baseline schedule and continue through completion, based on a review of the project records and other related information.

Experts such as Holloway Consulting performing retrospective schedule analysis and offering opinions on delays, impacts, acceleration, labor productivity losses, etc., are sometimes faced with situations where schedule updates are not available. Situations might occur where the contractor did not develop a baseline or contract schedule, thus leaving the expert with few if any contemporaneous tools upon which to base the analysis. In such situations, the construction delay analysis expert may have no alternative but to base the analysis on as-planned and as-built schedules created retrospectively from the project records.

Contact Steve Holloway – (303) 984-1941 about your construction claim

Holloway Consulting
Construction Schedule Delay Analysis Experts
10885 W. Beloit Pl
Lakewood, CO 80227
Denver Phone: (303) 984-1941
Fax: (303) 716-0432

Email: steve.holloway@disputesinconstruction.com
Blog: disputesinconstruction.com
Web: hcgexperts.com

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