Retrospective method
As-built critical path and longest path
Build the as-built programme, trace the longest continuous path to completion, and identify what drove it.
- Jurisdiction
- General method guidance, not jurisdiction specific
- Law and editions as at
- 3 August 2026
- Last reviewed
- 3 August 2026
- Editorial status
- Editorial draft, not yet independently reviewed
The question it answers
What actually controlled completion, as a matter of fact?
Fact-led retrospective enquiry, particularly where the tribunal has signalled that it wants the facts rather than a model.
Minimum evidence
- Reliable as-built dates and sequence
- Evidence of constraints, access and resource decisions
- Witness evidence about what the site was actually waiting for
The strength of this family is that it starts from facts rather than from a plan or a model. Its weakness is that a poor as-built record makes the whole exercise an act of reconstruction, and reconstruction imports assumptions.
Corroboration is what makes it persuasive: minutes, look-aheads, procurement records and testimony that all point at the same controlling constraint in the same period.
Strengths
- Foregrounds what was really controlling the work rather than what a model calculates
- Corroborates well with site evidence and contemporaneous decisions
Frequent failures
- The longest chain mistaken for causation
- As-built history reconstructed rather than recorded
- Constraints inferred backwards from the claim
Mandatory caution
The longest path shows what took the time. It does not show who was responsible for it, and it does not decide entitlement.
Other methods
Where the record comes in
Every mechanism on this page turns on evidence: what happened, what was known and when. A record built as the job happens is worth more than any argument assembled afterwards. Construction Metric keeps that record automatically, from the messages, photographs and voice notes a site team already sends.
Built by AI Metric
The analysis on this site is only as fast as the evidence behind it. AI Metric builds bespoke systems for consultancies, contractors and claims teams: document and correspondence triage, event registers assembled from the project record, programme and cost reconciliation, and drafting support that always cites the document it came from. Built for review by your own experts, never to replace their judgement.
Do not overread this page
No method decides entitlement, and no method is court approved. A method is fit when it answers the relevant question with the reliable data available, respects the contract and the governing law, and survives alternative explanations. The choice must be explained and defended, not asserted.
General explanation of how contract mechanisms, analysis methods and legal principles generally work. It is not legal or contractual advice, not an opinion on any project, and no standard-form contract wording is reproduced anywhere on this site. Standard forms are routinely amended, so every default described here, including every time period, can be different on your project. Your executed contract, as amended, and the governing law and forum always control. Deadlines may already be running: if an event has occurred, preserve your position and take qualified advice.