Fai Revalidation

FAI Revalidation (manufacturing-quality/as9102/fai-revalidation)

Use when the task is scheduling a first article inspection (FAI) revalidation per AS9102 practice: the revalidation due date comes from the last FAI date plus the revalidation interval, a change can pull the schedule earlier, and the re-validation re-verifies the affected characteristics plus every key characteristic.

Domain quick reference

• Time-driven revalidation: the due date is the last FAI date plus the revalidation interval; the default policy is annual (365 days).
• revalidation_status returns due_date, days_remaining, and status: due on or past the due date, upcoming within the 60-day window before it, current otherwise.
• Change-driven revalidation: a process, tooling, drawing-revision, location, or supplier change triggers a revalidation; a part-number or material change calls for a new FAI instead; no change means time-driven only.
• next_revalidation_date takes the later of the time-driven due date and the change-driven date (change date plus the interval); an early change cannot pull the schedule earlier.
• revalidation_scope returns the characteristics to re-verify: the affected characteristics plus every key characteristic, deduplicated in order; key characteristics always stay in scope.
• AS9102 frames revalidation around the first article inspection practice; the schedule model here is a practical summary, not clause text.

Workflow

1. Confirm the last FAI date and the revalidation interval; use revalidation_due_date for the time-driven due date.
2. Check the schedule with revalidation_status(last_fai_date, today); act on status due or upcoming.
3. When a change occurred, classify it with change_trigger_verdict: revalidation-required, new-fai-required, or not-triggered.
4. Combine the schedule with the change date using next_revalidation_date for the single next due date.
5. Scope the re-verification with revalidation_scope(affected, key_characteristics); key characteristics always stay in scope.
6. Record the due date and the scope in the revalidation plan.

Pitfalls

• Zero or negative intervals: interval_days must be positive; revalidation_due_date raises ValueError otherwise.
• Treating a part number or material change as revalidation: those call for a new FAI, not a revalidation (change_trigger_verdict returns new-fai-required).
• Pulling the schedule earlier with an old change: a change date before the last FAI date cannot move the due date; the later date wins.
• Forgetting key characteristics: revalidation re-verifies the affected characteristics plus every key characteristic, even when the change list is empty.
• Non-date inputs: last_fai_date, today, and change_date must be datetime.date instances; strings raise ValueError.
• Reporting days remaining from a string date: compute the status with real date objects so the day arithmetic is exact.

Behavior contract (gate 3)

The revalidation logic is exercised by the gate 3 contract test: scripts/test_fai_revalidation.py against scripts/fai_revalidation_logic.py (stdlib unittest, offline). Run: python3 scripts/test_fai_revalidation.py

Compliance

• Standards referenced, not reproduced: AS9102 revalidation practice is summarized as a schedule and scope model, common aerospace first article practice per standards-map.yaml.
• compliance: STANDARDS-REF, gated: false.