Which delay analysis method is most credible in litigation?

Tribunals generally favour methods that are contemporaneous and use the actual schedule updates available at the time — Windows and Time-Impact Analyses. Retrospective methods are accepted but scrutinised more heavily.

What is concurrent delay?

Two or more delay events, attributable to different parties, occurring at the same time and each capable of delaying the project independently. Treatment varies by jurisdiction and contract.

Which calculators on PMMilestone.org apply to Delay Analysis?

For Delay Analysis, the most relevant tools on the flagship platform are the EVM, SPI and CPI calculators on PMMilestone.org. They reproduce the formulas referenced in this entry against your own project data.

What is a common misconception about Delay Analysis?

That the topic is well-defined across all references. In practice, definitions vary between PMBOK, PRINCE2, AACE and ISO 21500 — this entry uses the definition most aligned with field practice on capital projects, and flags where the standards diverge.

Which related encyclopedia entries should I read alongside Delay Analysis?

Read Earned Value Management, Critical Path Method and the DCMA 14-point assessment next. The full A–Z is available in the PMMilestone Encyclopedia, and quick one-line definitions live in the PM Glossary on the flagship platform.

How does Dr. Hassan Eliwa's research treat Delay Analysis?

Dr. Hassan Eliwa's research focuses on owner-side project controls, schedule integrity and forensic delay analysis on capital construction and power programmes. Delay Analysis is treated through that lens — what a planning or controls engineer is expected to do with it on a live project, not its textbook definition alone. See the full research library at PMMilestone Research Articles.

How is Delay Analysis defined on PMMilestone Research & Insights?

Forensic and prospective techniques used to identify, quantify, and apportion responsibility for schedule delay. For the full treatment, see the definition, principles, applications and related entries above — every encyclopedia entry follows the same research-grade structure.

Forensic / Claims · Letter D

Delay Analysis

Forensic and prospective techniques used to identify, quantify, and apportion responsibility for schedule delay.

By Dr. Hassan Khames Eliwa, PhD · Updated 2025-04-29

Definition

Delay Analysis is the structured evaluation of schedule changes to determine the cause, impact, criticality, and responsibility for delay. It supports contractual time-extension claims, extension-of-time entitlement, prolongation cost recovery, and dispute resolution.

Principles & Methods

AACE Recommended Practice 29R-03 codifies the principal techniques:

As-Planned vs As-Built (MIP 3.1) — visual comparison of baseline against actuals.
Impacted As-Planned (MIP 3.6) — insert delay events into the baseline and recompute.
Collapsed As-Built (MIP 3.7) — remove delay events from the as-built and recompute.
Time-Impact Analysis (MIP 3.7) — model each delay prospectively at the time it occurred.
Windows Analysis (MIP 3.4) — split the project into time windows and analyse contemporaneously.

Applications

Used by owners, contractors, expert witnesses, and adjudicators on construction, EPC, and infrastructure disputes. Windows and Time-Impact analyses are the methods most commonly accepted by international tribunals.

Best Practices

Maintain a contemporaneous, properly statused schedule throughout the project — most disputes are won or lost here.
Document delay events as they occur with notices, photographs, and daily reports.
Match the analysis method to the contract requirements and the data available.

Common Mistakes

Choosing a method after the fact to support a preferred conclusion.
Ignoring concurrent delay.
Relying solely on the baseline without considering as-built progress.

References

AACE International, RP 29R-03 — Forensic Schedule Analysis.
SCL, Delay and Disruption Protocol, 2nd ed., 2017.

Frequently Asked Questions

Which delay analysis method is most credible in litigation?
Tribunals generally favour methods that are contemporaneous and use the actual schedule updates available at the time — Windows and Time-Impact Analyses. Retrospective methods are accepted but scrutinised more heavily.
What is concurrent delay?
Two or more delay events, attributable to different parties, occurring at the same time and each capable of delaying the project independently. Treatment varies by jurisdiction and contract.
Which calculators on PMMilestone.org apply to Delay Analysis?
For Delay Analysis, the most relevant tools on the flagship platform are the EVM, SPI and CPI calculators on PMMilestone.org. They reproduce the formulas referenced in this entry against your own project data.
What is a common misconception about Delay Analysis?
That the topic is well-defined across all references. In practice, definitions vary between PMBOK, PRINCE2, AACE and ISO 21500 — this entry uses the definition most aligned with field practice on capital projects, and flags where the standards diverge.
Which related encyclopedia entries should I read alongside Delay Analysis?
Read Earned Value Management, Critical Path Method and the DCMA 14-point assessment next. The full A–Z is available in the PMMilestone Encyclopedia, and quick one-line definitions live in the PM Glossary on the flagship platform.
How does Dr. Hassan Eliwa's research treat Delay Analysis?
Dr. Hassan Eliwa's research focuses on owner-side project controls, schedule integrity and forensic delay analysis on capital construction and power programmes. Delay Analysis is treated through that lens — what a planning or controls engineer is expected to do with it on a live project, not its textbook definition alone. See the full research library at PMMilestone Research Articles.
How is Delay Analysis defined on PMMilestone Research & Insights?
Forensic and prospective techniques used to identify, quantify, and apportion responsibility for schedule delay. For the full treatment, see the definition, principles, applications and related entries above — every encyclopedia entry follows the same research-grade structure.