Understanding Time Impact Analysis: A Contractor'\''s Guide

What Is a Time Impact Analysis?

A Time Impact Analysis (TIA) is a prospective schedule analysis technique used to determine the impact of a specific delay event on the project completion date. It is the gold standard methodology accepted by AACE International (Recommended Practice 29R-03) and is required or preferred by most federal agencies including USACE, NAVFAC, and the VA.

Unlike retrospective delay analysis methods that look backward at what happened, a TIA is performed at or near the time of the delay event, using the schedule status current at that point. This makes it the most accurate and defensible approach for quantifying delay impacts.

When Do You Need a TIA?

You should prepare a TIA whenever a delay event occurs that was not the contractor's responsibility and that may impact the project completion date. Common triggers include owner-directed changes or additional scope, design errors or omissions requiring RFI resolution, differing site conditions, force majeure events (weather, pandemics, civil unrest), and delayed owner-furnished equipment or materials.

The TIA Process: Step by Step

Step 1: Establish the Baseline for Analysis

Start with the most recent approved schedule update that reflects the project status just before the delay event occurred. This is your "unimpacted" schedule — it shows what the completion date would have been without the delay.

Step 2: Develop the Delay Fragnet

A fragnet (fragment network) is a small network of activities that represents the delay event and its logical connections to the existing schedule. The fragnet should include the delay activity itself with its duration, logical ties to the existing schedule activities affected, and any resulting out-of-sequence work or acceleration.

Step 3: Insert the Fragnet and Recalculate

Insert the delay fragnet into the unimpacted schedule and run the CPM calculation. The difference between the original completion date and the new calculated completion date represents the time impact of the delay event.

Step 4: Document the Analysis

Prepare a formal TIA report that includes an executive summary of the delay event and its impact, a narrative description of the delay circumstances, before-and-after schedule comparisons, the fragnet logic diagram, the calculated time impact in calendar and working days, and supporting documentation (RFIs, change orders, correspondence).

Common TIA Mistakes to Avoid

• Using the wrong base schedule: The analysis must use the schedule status current at the time of the delay, not the original baseline or the latest update.
• Ignoring concurrent delays: If contractor-caused delays are occurring simultaneously, the TIA must account for concurrency to isolate the owner-responsible impact.
• Insufficient documentation: Every assumption and data point in the TIA must be supported by project records. Unsupported claims will be challenged.
• Waiting too long: Prospective TIAs prepared near the time of the event are far more defensible than retrospective analyses prepared months or years later.
• Not verifying the critical path: A delay event only impacts the completion date if it affects activities on the critical path. Verify that the impacted activities are indeed critical before claiming a time extension.

TIA Best Practices

Based on our experience preparing TIAs for federal, commercial, and data center projects, here are the practices that produce the most defensible results.

First, maintain contemporaneous schedule updates. The quality of your TIA is directly proportional to the quality of your schedule updates. If your monthly updates are inaccurate, your TIA will inherit those inaccuracies.

Second, prepare TIAs promptly. Submit the analysis within 30 days of the delay event whenever possible. Prompt submission demonstrates good faith and strengthens credibility.

Third, use clear and professional formatting. The TIA report will be reviewed by project managers, construction managers, and potentially attorneys. Clear writing, professional graphics, and organized documentation make the analysis easier to understand and accept.