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Overview

Action Priority (AP) determines which failure modes require immediate corrective action. TestAuto2 — Automotive Safety Solution uses the AIAG-VDA FMEA methodology to automatically calculate AP from Severity, Occurrence, and Detection ratings, classifying risks as High (H), Medium (M), or Low (L).

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Understanding Action Priority Levels

PriorityColorRPN ThresholdMeaning
H - HighRedRPN > 100 or S≥8 + O≥7Corrective action required
M - MediumOrange40 < RPN ≤ 100Action should be taken
L - LowGreenRPN ≤ 40Action optional
TestAuto2 implements AIAG-VDA FMEA 4th Edition methodology, which uses Action Priority tables instead of simple RPN thresholds. High priority is automatically assigned when Severity ≥8 or when the S-O-D combination exceeds risk tolerance per the AIAG-VDA decision matrix.

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Calculate Pre-Mitigation Action Priority

Action Priority is automatically calculated after you complete the S-O-D ratings:
  1. Open your FMEA risksheet (SFMEA, DFMEA, or PFMEA document)
  2. Navigate to the Initial Assessment view from the risksheet view selector
  3. Verify S-O-D ratings are complete for the failure mode:
    • Severity (1-10): Effect impact rating
    • Occurrence (0-10): Failure probability rating
    • Detection (0-10): Control effectiveness rating
  4. Check the Pre-Mitigation AP column — the formula automatically calculates: 
    IF Severity ≥ 8 THEN H
ELSE IF RPN > 100 THEN H
ELSE IF RPN > 40 THEN M
ELSE L
  5. Review the color-coded result in the premitigationAP cell:
    • Red badge with “H” = High priority
    • Orange badge with “M” = Medium priority
    • Green badge with “L” = Low priority
If any S-O-D field shows “Undetermined” (default value), the Action Priority formula cannot execute. You’ll see an empty AP cell. Complete all three ratings before expecting AP results.

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Action Priority Decision Logic

The automatic formula implements this decision matrix: diagram Example Calculations:
  • S=9, O=6, D=5 → RPN=270 → H (Severity ≥8 rule)
  • S=7, O=8, D=7 → RPN=392 → H (RPN >100 rule)
  • S=6, O=4, D=3 → RPN=72 → M (40 < RPN ≤100)
  • S=4, O=2, D=3 → RPN=24 → L (RPN ≤40)

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Calculate Post-Mitigation Action Priority

After implementing risk controls, recalculate AP to demonstrate risk reduction:
  1. Link risk controls to the failure mode cause using the Risk Controls column (see Link to Risk Controls)
  2. Navigate to the Final Evaluation view in the risksheet
  3. Update post-mitigation ratings:
    • postmitigationFMOccurrence — reduced likelihood after prevention controls
    • postmitigationDetection — improved detection after verification controls
    • Note: Severity remains unchanged (inherent to the effect)
  4. Review the Post-Mitigation AP column — automatically recalculates using updated O and D values: 
    RPN_post = Severity × postmitigationFMOccurrence × postmitigationDetection
  5. Verify risk reduction by comparing row header colors:
    • Row headers inherit color from apNew (post-mitigation AP)
    • Red rows still require additional controls
    • Green rows demonstrate effective risk reduction
Use the risksheet view selector to filter by Action Priority. The “High Priority Only” view shows only H-rated failure modes, allowing teams to focus mitigation efforts on the most critical risks first. Address all high-priority items before moving to medium and low priorities.

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Interpret Action Priority Results

AP ResultRequired ActionDocumentation
HMandatory corrective actionCreate linked risk control tasks with assigned owners and due dates. Document mitigation plan in FMEA report.
MRecommended actionEvaluate cost-benefit of mitigation. Document decision rationale if no action taken.
LOptional improvementConsider for continuous improvement. No mandatory action required.
In automotive functional safety projects, any failure mode with Severity ≥8 (potentially life-threatening) automatically receives High priority regardless of RPN. This ensures safety-critical items are never deprioritized due to low occurrence or good detection.

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Verification Steps

After calculating Action Priority, verify:
  1. All failure modes have AP assigned — no empty cells in Pre-Mitigation AP column
  2. High-priority items have linked risk controls — check Risk Controls column shows task IDs
  3. Post-mitigation AP shows improvement — compare traffic light colors (red→orange or red→green)
  4. Row header colors reflect residual risk — sorted by post-mitigation AP for global visibility
Expected behavior: When you sort the FMEA by Action Priority (ascending), all H-priority rows appear first due to the built-in sort order (0=H, 1=M, 2=L).

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See Also