Action Priority Ap

Action Priority (AP) — AIAG-VDA 2019

Goal

Assign and audit Action Priority (AP) ratings correctly using the AIAG-VDA 2019 method, ensuring high-risk items receive justified action or formal risk acceptance. This skill is used when classifying risk levels in PFMEA or DFMEA, reviewing existing ratings, or auditing FMEA documents for AP compliance.

Required AP Review Checklist

☐ Confirm the linked Failure Effect, Failure Mode, and Failure Cause are correct before assigning AP ☐ Confirm S is based on the Failure Effect (severity to the customer or end user) ☐ Confirm O is based on the Failure Cause with current prevention controls in place ☐ Confirm D is based on current detection controls for this Failure Mode ☐ All S, O, and D ratings are supported by data, field history, capability data, or documented engineering judgement — not guesses ☐ Assign AP using the full AP determination rules (see ap-table.md) — not only the summary patterns in this skill ☐ For formal PPAP submissions, customer-facing FMEAs, or any disputed rating, confirm against your licensed AIAG-VDA FMEA Handbook — the rating criteria that make an S, O or D value defensible are in the handbook, not in this skill ☐ For every H-AP item: define a corrective action with owner and target date, or document a formal escalation rationale ☐ Reassess AP only after the corrective action is implemented and verified — not when only planned ☐ Verify Special Characteristics are rated S = 9 or 10 ☐ Document the evaluation decision for every M-AP item (action taken or rationale for no action) ☐ Document rationale for every L-AP item

Why AP replaces RPN

The legacy RPN = Severity × Occurrence × Detection had critical flaws:

Problem 1 — Same RPN, very different risk

• S=6, O=6, D=6 → RPN = 216
• S=9, O=8, D=3 → RPN = 216 The second scenario involves a safety-related severity (S=9) and high occurrence — far more dangerous — yet produces the same RPN.

Problem 2 — Easy to game Teams learned to lower RPN cheaply by improving detection (adding an inspection step). D: 8→3 drops RPN by 62.5%. But the defect is still being made — it's just being caught later. Prevention (reducing occurrence) is harder but far more valuable.

Problem 3 — No mandatory threshold RPN had no defined threshold for mandatory action. "High RPN" meant different things to different teams and customers.

The AP fix:

• S=9 or S=10 → always H (mandatory action), regardless of O and D
• AP looks at S and O together first (risk of harm occurring), then considers D
• Requires documented action or documented rationale for no action

AP Classification

H — High Priority

Action required. Assign a responsible person and a target completion date.

If no improvement is achievable (technically or economically), the team must:

1. Document why no action is possible
2. Escalate to management for acceptance of residual risk
3. Get management sign-off

H-AP items must never be silently ignored.

Conditions that always produce H:

• S = 9 or 10 (any O, any D)
• S = 8 + O = 6–10 + D = 6–10

M — Medium Priority

Action recommended. The team should evaluate whether risk reduction is beneficial.

M-AP does not mean "no action needed." It means action is not mandatory, but the team must document its evaluation decision:

• Action taken → describe the action
• No action → document why (risk accepted, cost-prohibitive, technically infeasible)

L — Low Priority

No action required. Document rationale for the record.

AP Assessment Workflow

This skill explains AP logic and decision patterns. Use the full AP determination rules (ap-table.md) for final rating assignment. Do not rely solely on the summary patterns below for disputed cases or formal PPAP submissions — those require the rating criteria in your licensed AIAG-VDA FMEA Handbook.

Before assigning AP: Do not assign AP unless S, O, and D are already justified based on the linked failure effect, failure cause, and current controls. AP is only as good as the ratings it is built on.

For each FC (Failure Cause) row in the PFMEA/DFMEA:

1. Assign S (for the linked Failure Effect)
2. Is S = 9 or 10?
   → Yes: AP = H. Done.
   → No: continue

3. Assign O (for this Failure Cause with current prevention controls)
4. Assign D (for this Failure Mode with current detection controls)
5. Look up AP in the full table (see ../pfmea-process/assets/ap-table.md)

All S, O, and D ratings must be supported by test data, field history, capability data, or documented engineering judgement.