When a delay claim reaches the review stage — whether by an owner, a claims consultant, or legal counsel — the first question is almost always about methodology. How was the delay quantified? What analysis technique was used? Is it the right one for this situation?
The choice of forensic delay methodology is not a technicality. It determines whether your analysis is accepted as credible or dismissed before anyone reads past the executive summary.
The Main Forensic Methodologies
Time Impact Analysis (TIA)
TIA is a prospective or retrospective analysis that inserts a specific delay event into the accepted baseline schedule at the point in time when the event occurred, and measures the resulting push to the completion date. It is the most widely accepted methodology by public agencies — USACE, Caltrans, Port Authority, and most state DOTs specify TIA in their scheduling specifications.
TIA works best when there is a well-developed baseline schedule with honest logic and float, and when the delay events are discrete and documentable. It loses credibility when the baseline schedule was poorly constructed or when float was artificially constrained from the start.
Windows Analysis
Windows analysis divides the project into time periods and analyzes the critical path within each window separately. It is the most rigorous methodology for complex projects with multiple concurrent delays from both parties, because it can isolate which delays were owner-caused, which were contractor-caused, and whether they were concurrent.
It requires a complete set of schedule updates and contemporaneous project records. It is time-consuming but produces the most defensible result on complicated claims.
Collapsed As-Built
The collapsed as-built methodology starts with the actual as-built schedule and removes the owner-caused delay events to show what the completion date would have been without those delays. The difference between the actual completion and the collapsed completion represents the compensable delay.
It is often used when the project is complete and a good baseline was never established, because it works backward from what actually happened. It is more vulnerable to challenge than TIA because it relies heavily on assumptions about what would have occurred absent the delay.
How to Choose
The right methodology depends on three factors: the quality of the schedule record, the nature of the delay events, and what the owner or agency will accept. If your contract specifies TIA, use TIA. If you have a complete set of updates and multiple concurrent delay events, windows analysis is the more defensible choice. If the project is complete and the schedule record is thin, collapsed as-built may be your only option — but document your assumptions carefully.
The worst outcome is choosing a methodology because it produces the largest number, rather than because it is the most appropriate for the available project record. An experienced claims reviewer will identify that immediately.