Every revision in this window has pushed the completion date later. No period recovered time — the drift is monotonic, which is the pattern that most reliably precedes a serious overrun.
| Revision | Data date | Forecast finish | Period slip | Cumulative | Delay introduced by |
|---|---|---|---|---|---|
| R9 | 30 Nov 25 | 22 Oct 27 | — | 0d | Reference revision |
| R10 | 31 Dec 25 | 1 Nov 27 | +10d | +10d | Structural steel procurement re-sequenced (Grid G package) |
| R11 | 31 Jan 26 | 9 Nov 27 | +8d | +18d | Level 3 pre-pour held pending RFI-214 (employer) |
| R12 | 28 Feb 26 | 19 Nov 27 | +10d | +18d* | Grid G erection rework + MEP logic closed |
| Net drift over the window (R9 → R12) | +28d | *+18d vs R10 baseline of record | |||
Across four consecutive revisions the forecast completion of Tower C has moved steadily later, from 22 October 2027 at R9 to 19 November 2027 at R12 — a cumulative drift of 28 calendar days over three reporting periods, and 18 days against the R10 baseline of record. Critically, no period recovered any time: each update added delay. A monotonic drift of this kind is a stronger warning than any single large slip, because it shows the programme is losing ground systematically rather than absorbing a one-off event.
The delay did not arrive all at once, and tracing it period by period shows a migrating cause. The first slip (R9→R10, +10 days) came from re-sequencing the Grid G structural steel package during procurement. The second (R10→R11, +8 days) was an employer-side event — the Level 3 pre-pour held for a response to RFI-214. The third (R11→R12, +10 days) returned to the steel scope as the Grid G erection sequence was reworked, compounded by previously open logic on the MEP rough-in being closed.
The practical implication is that the Grid G structural steel package is the recurring driver: it introduced delay in two of the three periods and remains on the critical path. Recovery effort concentrated there will do more to arrest the trend than attention spread across the programme. The single employer-side event (RFI-214) is quantified separately and is relevant to any extension-of-time position — it is examined in full in the Claim Brief.
Cross-update matching. Activities are reconciled across all four revisions by unique Activity ID, with a name-and-WBS fallback for re-coded activities, so a slip is tracked to the same physical work across the series even where IDs or descriptions change.
Period attribution. Each period's slip is the movement of the forecast completion date between consecutive data dates. The "delay introduced by" column identifies the activities on or joining the critical path that account for that period's movement.
Limitation. The trend reflects the schedules as submitted at each data date. It does not incorporate correspondence or site records beyond what the schedules encode. Forensic entitlement for the employer-side and contractor-side events is addressed by the Claim Brief, not this trend report.
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