Concurrent Delay in Construction: Analysis and Legal Implications

One of the Hardest Problems in Forensic Scheduling

Concurrent delay occurs when two or more independent delay events overlap in time and both impact the project's critical path. It is one of the most complex and contested issues in forensic schedule analysis — and one of the most consequential, because concurrency determines whether a contractor is entitled to time extension, liquidated damages, or both.

Understanding concurrent delay is essential for anyone involved in construction claims, whether as a contractor, owner, or consultant.

Defining Concurrent Delay

True concurrent delay has three characteristics:

• Independent Causes: The delays have separate root causes — one is not caused by or dependent on the other.
• Critical Path Impact: Both delays independently impact the critical path during the overlapping period.
• Different Responsibility: The delays are caused by different parties (typically one owner-caused and one contractor-caused).

If any of these characteristics is missing, the delay may not be truly concurrent. For example, sequential delays where one completes before the other begins are not concurrent. Similarly, delays where both are caused by the same party are not concurrent in the legal sense.

Types of Concurrent Delay

True Concurrency

Both delays occur during exactly the same time period and both affect the critical path. This is the clearest case of concurrency.

Partial Concurrency

The delays overlap for some period but not for their entire duration. Analysis must determine the extent of overlap and the impact during the concurrent period.

Sequential Concurrent

Sometimes courts and contracts treat delays as concurrent even if they don't literally overlap in time, if both would have impacted the project at the same point. This interpretation varies by jurisdiction.

Why Concurrency Matters

The legal and contractual implications of concurrent delay are significant:

• Time Extension: If owner-caused delay is concurrent with contractor-caused delay, the contractor may be entitled to a time extension (preventing LDs) but not to additional compensation.
• Liquidated Damages: Owner cannot assess LDs for delay attributable to owner's own actions, even if contractor was also delaying.
• Additional Compensation: Contractor generally cannot recover extended overhead or delay damages for periods of concurrent delay.
• Apportionment: In some jurisdictions, delays can be apportioned between parties based on responsibility.

Analysis Methodologies

Time Impact Analysis for Each Delay

The most rigorous approach is to perform separate TIAs for each delay event and compare results. If both TIAs show the same critical path impact during the same period, you have concurrent delay.

Critical Path Review

Examine the critical path during the period of alleged concurrency. Is the critical path running through activities affected by the owner's delay, the contractor's delay, or both? Parallel critical paths are evidence of concurrent delay.

Daily Window Analysis

For detailed analysis, evaluate each day or week of the delay period to determine which party's actions were driving the critical path that day. This granular approach reveals whether concurrency is continuous or intermittent.

Common Concurrency Scenarios

Weather During Design Delays

Scenario: Owner fails to respond to an RFI for 30 days. During the same 30 days, severe weather would have prevented the affected work anyway. If both delays impact the critical path, this is concurrent delay.

Procurement vs Labor

Scenario: Owner-furnished equipment is delayed 20 days. During the same period, contractor's crew was unavailable due to project management issues. Both delays impact the critical path of the affected work. This is concurrent delay if the crew issue was independent of the equipment delay.

Design Conflict vs Quality Issues

Scenario: Owner's design shows a conflict requiring resolution. While awaiting resolution, contractor's installed work is rejected due to quality defects requiring rework. Both delays impact the same activity chain. This requires careful analysis to determine responsibility.

Defending Against Concurrency Claims

If you are defending against a claim that your delay is concurrent with the other party's delay, consider these arguments:

• Pacing Delay: Your actions were a reasonable response to the other party's delay, not an independent delay cause.
• Critical Path: The other party's delay was not on the critical path at the time of the alleged concurrency.
• Duration Mismatch: The delays don't actually overlap, or overlap only partially.
• Causation: The other party's delay caused or enabled your delay, making it not truly independent.

Jurisdiction Matters

Concurrent delay law varies significantly between jurisdictions. Some follow strict apportionment rules, others apply the "Malmaison approach" granting time extension but no compensation, still others follow contract language exclusively. When delays become contested, engaging legal counsel familiar with the specific jurisdiction is essential.

Prevention Strategies

The best defense against concurrency disputes is prevention:

• Maintain accurate contemporaneous schedules showing true critical path at all times.
• Document delay events promptly with detailed records of cause, duration, and impact.
• Distinguish clearly between excusable and non-excusable delays in project records.
• Address potential delays through Requests for Time Extension as they occur, not at project end.
• Maintain daily logs that record critical path activities and any impediments affecting them.

Final Thoughts

Concurrent delay is where forensic scheduling becomes genuinely difficult. The technical analysis is only part of the challenge — the legal framework, contract interpretation, and factual documentation all play crucial roles. When concurrency is in dispute, the outcome often depends more on the quality of contemporaneous records and the persuasiveness of the analysis than on the raw CPM calculations.

For significant delay claims involving concurrency, engage experienced forensic scheduling experts and legal counsel early. The cost is small compared to the stakes involved.