// evidence pack · EV-2026-0147 · immutable record

Variation Order VO-23 — Substructure redesign, Plot 4

Aberdeen Grove development · Contract NEC4 Option A · Pack generated 12 Jul 2026 · Retention: 12 years (contract + 6)

Decision summary

FieldValue
RequestApprove variation VO-23: revised pad foundations following ground investigation, +£48,250.00, +11 working days
OutcomeAPPROVED WITH CONDITIONS — condition: revised programme issued within 5 working days
Total elapsed47 days beyond native 28-day flow limit — vault kept the approval alive, chased, and escalated
Approved documentVO-23-RevC.pdf (the version approved — not the latest version) · SHA-256 9f2e…c41a
Approvers2 of 2 required: Contracts Manager + Commercial Director (delegated)

Decision chain (immutable, hash-linked)

26 May 2026 14:02 — Request raised
By J. Fraser (Site QS) via Teams adaptive card · attachments: VO-23-RevA.pdf, GI report · entry hash a1b4…
28 May 2026 09:15 — Clarification requested
R. Mackie (Contracts Manager): "Revised drainage detail needed before I approve." Status → awaiting info
9 Jun 2026 11:47 — Document revised
VO-23-RevB.pdf superseded by RevC · versions retained, approval re-anchored to RevC · entry hash 7c9d…
16 Jun 2026 08:00 — Reminder #2 escalated
No response 5 working days → escalation rule fired → Commercial Director added per delegation matrix
24 Jun 2026 16:31 — Approval 1 of 2
R. Mackie APPROVED RevC · IP + device recorded · entry hash e2f8…
2 Jul 2026 — Absence handling
A. Grant on leave (Outlook OOF detected) → delegated to S. Lindsay per standing delegation, recorded with authority reference
11 Jul 2026 10:22 — Approval 2 of 2 · DECISION
S. Lindsay APPROVED WITH CONDITIONS · full comment retained · entry hash 03aa…
12 Jul 2026 — Signed evidence pack generated
This document · chain verified end-to-end · TAMPER CHECK PASSED

Why native tooling couldn't hold this

GapWhat happened here
Power Automate approval flows time out at 28 daysThis decision took 47 days — the vault owns the wait, reminders and escalation instead of the flow
No immutable audit trailHash-linked entries + signed pack = audit evidence (ISO 9001 §7.5.3 control of documented information)
Approval of *which version*?Vault pins the decision to the exact document hash approved (RevC), retaining superseded versions
Absence & delegationRecorded against the delegation matrix, not ad-hoc email forwarding
Approval Evidence Vault · a Cairn Labs concept · vertical template shown: construction variations (NEC4). Also: QMS document control, procurement exceptions, housing compliance certificates. labs.cairnautomation.co.uk