Delay Analysis
What Is Delay Analysis in Construction?
Delay analysis is the disciplined process of establishing what actually moved a project's completion date — and who is entitled to time or money as a result. Being late is not the same as being entitled.
The question it answers
On almost every major programme, work finishes later than planned. Delay analysis exists to answer a harder question than “are we late?” — it asks what specifically caused the completion date to move, by how much, and whose risk that was under the contract. The output is an entitlement: a number of days, supported by evidence.
Delay to completion vs consumed float
The single most important distinction is between delay to completion and mere consumption of float. An activity can slip for weeks without delaying the project if it was never on the critical path. Delay analysis measures effect on the completion date, not disruption in general — which is why a credible analysis lives or dies on the quality of the programme’s logic.
The main methods
Several recognised methods exist, and the right one depends on the timing and the records available:
- Time Impact Analysis — modelling an event into the programme current at the time (covered in the TIA guide).
- Windows / time-slice — assessing delay period by period.
- As-planned vs as-built — comparing intended and actual sequences.
- Impacted as-planned and collapsed as-built — used where records constrain the options.
The full treatment is on the construction delay analysis page.
Why records decide it
A delay analysis is only as strong as the contemporaneous record behind it — programmes, progress updates, correspondence and change. A case built as events unfolded beats one reconstructed after the fact, every time. This is why disciplined schedule assurance during delivery is really claims preparation done early.
Fact vs opinion
Good delay analysis distinguishes what the records show from what is argued. Where entitlement is contested, the strongest position is the one another analyst could reproduce from the same evidence — as in a 291-day claim resolved to an approved 64 days. That is the standard the discipline is built to.
This is a general explanation of professional practice, not legal or contractual advice.