The time impact analysis methodology, also referred to as TIA, is a technique that forecasts or predicts a delay’s effect on a project’s completion date. This schedule analysis method involves the insertion or addition of activities indicating delays or changes into the most recent schedule update prior to the delay event’s occurrence. This allows the analyst to determine the impact of a delay activity or series of delay activities on the project’s completion date.
The TIA is a prospective analysis methodology used during the course of the project to forecast or predict a delay’s effect on the project just before or as it is happening. This type of schedule analysis methodology is often required by contract for a contractor to receive an extension of time during project execution. This is in contrast to a retrospective method, which analyzes delays after they have occurred or after project completion.
The TIA starts with the most recent schedule update prior to the start of the delay being modelled. It is important that this schedule update accurately reflects progress on the project to that point in time and that the schedule logic accurately reflects the contractor’s plan for completing the remaining work. The analyst then creates a delay activity, or fragnet, that models the delay event and inserts it into the schedule update. This new schedule with the fragnet inserted can then be compared to the original schedule update. The variance in the project’s completion date represents the projected effect of the delay on the completion of the work. A simplified graphical representation of a time impact analysis, with the delay activity inserted and presented in red, is shown below:
It should be noted that there are several important considerations for choosing an appropriate analysis methodology. Each claim is unique and deals with different contract requirements, situational contexts, levels of documentation, complexities, legal jurisdictions, and dispute resolution forums, among other factors. The selection of a particular analysis method should be based on professional judgement, the documentation and data available, and diligent factual research and evaluation. Interface Consulting has addressed schedule delay issues on hundreds of construction-related matters, and its construction experts are skilled in preparing schedule delay analyses based on available data and client requirements.