Citable answer: A programme slip becomes a contractual notice issue when the delay or constraint triggers an obligation under the contract. The chain runs from site constraint to project warning to director-level exposure. Aven-AI ingests P6/MSP programmes to surface that chain early, before planning drift becomes a lost claim.
A bar on the programme moves to the right. On most projects, that is treated as a planning matter — something the scheduler reconciles at the next update. But a slip caused by an external event is rarely just a planning matter. It is often the visible end of a chain that runs: event → delay to an activity → impact on the critical path → entitlement to extension of time. And somewhere along that chain sits a contractual notice with a clock already running. Miss the connection and you lose a claim you were entitled to.
The chain, link by link
Link 1 — the event. Something happens that is not the contractor's risk: a late instruction, a variation, differing ground, an information delay.
Link 2 — the delay to an activity. The event holds up a specific work item. At this stage it may not even look serious.
Link 3 — the effect on the critical path. This is the link that decides whether there is a time claim at all. A delay only entitles you to an extension if it actually delays completion — which means it must hit the critical path. As the Institute of Construction Claims Practitioners (ICCP) put it, a delay event must impact the critical path of the programme before it can have any effect on the completion date (ICCP). Cause and effect is the bridge between the event and the entitlement.
Link 4 — the notice. Almost every standard form makes notice a precondition to relief. On FIDIC 1999, that is the 28-day notice under Sub-Clause 20.1, which — as Charles Russell Speechlys explain — is enforced as a condition precedent (Charles Russell Speechlys). Norton Rose Fulbright note that most contracts treat notice provisions as conditions precedent, so a failure to notify within the stipulated period can extinguish entitlement even where the delay is genuine (Norton Rose Fulbright).
Link 5 — the entitlement. Only if all four prior links hold does the extension of time, and any associated cost, survive.
Break any link and the chain fails. The most common break is not link 3, the technical one — it is link 4, the notice. The slip was real, the critical-path impact was real, but nobody served the notice in time because nobody connected the moving bar to the running clock.
Why the slip-to-notice connection gets missed
The programme and the contract are usually run by different people, in different systems, on different rhythms. The planner sees a bar move. The contracts team sees correspondence. The event that links them — the late instruction that caused the slip — lives in a third place, the document register. Each function is doing its job; the connection between them is what falls through.
There is also a timing mismatch. Programme updates often run monthly. The FIDIC notice clock runs in 28 days from awareness. A slip first visible in a mid-cycle update can already be deep into its notice period before the next formal review even surfaces it.
Proving the chain when the claim is challenged
When the claim is contested, it is the chain — not the headline number — that gets examined. The Society of Construction Law (SCL) Delay and Disruption Protocol stresses that the weight of any delay analysis rests on the availability of reliable, contemporaneous project records, a point drawn out in Claims Class's commentary on the Protocol (Society of Construction Law Protocol, via Claims Class). As Alvarez & Marsal observe, where analysis is done long after the event the SCL Protocol no longer points to a single preferred methodology — which makes the contemporaneous record, and a timely notice, more important, not less (Alvarez & Marsal).
In other words: a notice served while the event is fresh, supported by records that show cause and critical-path effect, is worth far more than a forensic reconstruction attempted two years later.
What a disciplined team does at the moment of a slip
- Ask "why" of every slip on the critical path. If the cause is an employer-risk event, the chain may already be live.
- Link the slip to its cause in the record — the instruction, RFI, or condition that drove it — so the notice has a basis.
- Start the notice clock from awareness of the event, not from the next programme update.
- Serve the notice, then build the cause-and-effect demonstration through the contemporaneous records.
Where a governed AI layer helps
The chain breaks because it crosses three systems and three people. A contract-aware layer that watches the programme, reads the contract's notice rules, and links a critical-path slip back to the event in the document record can flag, "this slip looks like the start of a notice clock — here is the likely cause and the deadline." The team confirms the cause-and-effect and serves the notice. The technology's job is to make sure the moving bar and the running clock are never looked at separately.
General guidance on delay and notice practice, not legal advice. Delay analysis and entitlement turn on the specific contract, records and governing law — take advice on your project.
Sources & further reading
- Institute of Construction Claims Practitioners (ICCP) — Extension of Time Claims: Cause and Effect. Source for the rule that a delay must hit the critical path before it affects the completion date: https://www.instituteccp.com/extension-of-time-claims-cause-and-effect/
- Charles Russell Speechlys — FIDIC time bar bites: Privy Council holds clause 20.1 is a condition precedent. Source for the FIDIC 28-day notice being enforced as a condition precedent: https://www.charlesrussellspeechlys.com/en/insights/expert-insights/construction-engineering-and-projects/2026/fidic-time-bar-bites--privy-council-holds-clause-20.1-is-a-condition-precedent/
- Norton Rose Fulbright — Time is ticking: Managing delay and extensions of time in construction contracts. Source for the point that most contracts treat notice provisions as conditions precedent: https://www.nortonrosefulbright.com/en/knowledge/publications/835d5fed/time-is-ticking-managing-delay-and-extensions-of-time-in-construction-contracts
- Society of Construction Law (SCL) Delay and Disruption Protocol, via Claims Class — Cause and Effect: The Key to Successful Construction Delay Analysis. Source for the weight the Protocol places on contemporaneous records: https://www.constructionclaimsclass.com/cause-and-effect-delay-analysis/
- Alvarez & Marsal — Delay Analyses in Construction Disputes: Limitations of Programme-Based Methods. Source for the point that there is no single preferred methodology once analysis is done long after the event: https://www.alvarezandmarsal.com/thought-leadership/delay-analyses-in-construction-disputes-limitations-of-programme-based-methods