Concurrent Delay Explained (Without the Legalese)

What Is Concurrent Delay?

Concurrent delay occurs when two or more independent delay events—one the contractor’s responsibility and one the owner’s—happen at the same time and both affect the critical path. In simple terms, the project is delayed by both parties simultaneously. The key legal consequence is that neither party may recover damages for the period of concurrency because each contributed to the delay. Understanding this concept is critical for anyone preparing or defending a delay claim.

Why Concurrent Delay Complicates Entitlement

In most contracts, an owner-caused delay entitles the contractor to an extension of time (EOT) and possibly compensation. A contractor-caused delay gives the owner the right to assess liquidated damages or deny an EOT. But when delays are concurrent, the general rule is that the contractor gets an EOT (since the owner’s delay also caused critical delay) but no compensation for extended overhead or other costs. The rationale: the contractor would have been delayed anyway by its own problem.

However, the law is not uniform. Some jurisdictions follow the “dominant cause” approach, where the predominant cause determines entitlement. Others apply the “but for” test. This makes schedule analysis even more important—you need to prove not just that delays overlapped, but that they were truly concurrent on the critical path.

How Analysts Identify Concurrent Delay in the Schedule

Identifying concurrent delay requires a robust schedule and proper update practices. Here are the steps analysts take:

1. Validate the Baseline and Updates

First, ensure the schedule is properly resource-loaded and logic-tied. Run DCMA 14-point checks to catch common issues like missing predecessors, negative lags, or long durations. A clean schedule is essential before any delay analysis.

2. Perform a Contemporaneous Period Analysis

Using the “windows” method, compare each update period’s as-built vs. as-planned critical path. Identify which delays occurred in each window and who caused them. If two delays both impact the critical path in the same period, concurrency may exist.

3. Use Fragnets or What-If Scenarios

Create a fragmentary network (fragnet) to model the owner delay and the contractor delay separately. Insert each into the schedule and see how the project completion date shifts. If removing one delay still leaves a delay due to the other, they are concurrent. Tools like Project Assure can help you quickly run these scenarios in your browser without uploading files.

4. Check for Non-Critical Path Overlaps

Concurrency only matters if both delays affect the critical path. A contractor delay on a non-critical path that becomes critical later is not concurrent with an owner delay that was already critical. Use float analysis to confirm both delays consumed all available float.

Practical Tips for Documenting Concurrent Delay

To strengthen your claim or defense, follow these documentation best practices:

• Maintain a detailed daily log: Record all events, including weather, owner changes, and subcontractor issues. Note start and end times.
• Update schedules monthly: Use a consistent update process. Retain all XER or .mpp files. The contemporaneous schedule is the best evidence.
• Separate delay causes in CPM logic: Use activity codes or separate paths for owner and contractor work. This makes it easier to isolate delays.
• Issue timely notices: Most contracts require notice within a set period. Failure to give notice can waive entitlement, even if the delay is owner-caused.
• Use a forensic delay analysis method: The most defensible methods are Time Impact Analysis (TIA) and Windows Analysis. Avoid simple “bar chart” comparisons.

Common Pitfalls to Avoid

Even experienced schedulers make mistakes. Watch out for:

• Pacing delays: When a contractor slows down work because of an owner delay, it is not true concurrency. The contractor’s delay is reactive, not independent.
• Float ownership arguments: Some contracts say float belongs to the owner. If the owner uses float first, the contractor’s later delay may not be concurrent because the owner’s delay already consumed the float.
• Ignoring non-critical delays that become critical: A delay that starts on a non-critical path can become critical later. You must analyze the entire delay period, not just the start.

Conclusion

Concurrent delay is one of the most contentious issues in construction claims. By understanding the definition, using proper schedule analysis techniques, and documenting diligently, you can protect your entitlement—whether you are the contractor seeking an EOT or the owner defending against a cost claim. Free tools like Project Assure make it easier to run DCMA checks and compare baselines vs. updates, all without uploading sensitive data. Use them to strengthen your next delay analysis.