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FMEA: RPN and Action Priority

Paste your failure modes with severity, occurrence and detection ratings to see which need action first under the AIAG-VDA criterion and how much the improvements cut the risk.

Pre-sizing and estimating tool: results do not replace design, calculations or reports signed by a licensed professional, nor verification against the applicable codes and standards.

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Analysis
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Paste straight from Excel (tabs) or separate with semicolons. Ratings from 1 to 10. Leave the revised columns blank until an action is in place.

—Failure modes with high Action Priority
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RPN Pareto

Failure modes from highest to lowest RPN, with the cumulative share. Bar color is the Action Priority: a high RPN is not always the most urgent.

Tap the chart to see the values.

RPN before and after actions

Comparison for the modes with revised S, O and D.

Tap the chart to see the values.

Severity × occurrence matrix

Number of failure modes in each cell; color is the highest Action Priority among them.

Failure mode ranking

The report gathers this page's inputs, results, equations, assumptions and references, with fields for project, engineer and revision. In the print dialog, choose Save as PDF.

Method, assumptions and references

Equations used

RPN = S × O × D (1 to 1000)
AP = AIAG-VDA table (S: 9–10, 7–8, 4–6, 2–3, 1; O: 8–10, 6–7, 4–5, 2–3, 1; D: 7–10, 5–6, 2–4, 1) → High, Medium or Low
Ranking order: AP, then S, then RPN; reduction = 1 − Σ revised RPN ÷ Σ original RPN (modes with actions)

Assumptions and limits

  • The AP table is the same for DFMEA and PFMEA in the AIAG-VDA handbook (1st edition, 2019). FMEA-MSR (monitoring and system response) uses a different table and is not implemented.
  • Ratings should follow the handbook severity, occurrence and detection tables, set by the cross-functional team. The calculator does not judge whether ratings were assigned correctly.

Standards and technical documents

  • AIAG & VDA: FMEA Handbook, 1st edition (2019), Action Priority tables
  • IEC 60812:2018: Failure modes and effects analysis (FMEA and FMECA)
  • SAE J1739:2021: Potential Failure Mode and Effects Analysis (FMEA) including design, process and MSR FMEA
  • AIAG: Potential Failure Mode and Effects Analysis (FMEA), 4th edition (2008)

U.S. regulations

  • 21 CFR Part 820: Quality Management System Regulation (risk management for medical devices)
  • MIL-STD-1629A: Procedures for performing a failure mode, effects and criticality analysis
  • OSHA 29 CFR 1910.119: process safety management (process hazard analysis)

Frequently asked questions

How do I calculate FMEA RPN?

Multiply severity, occurrence and detection, each from 1 to 10. A mode with S = 7, O = 6 and D = 5 has an RPN of 210.

What is Action Priority (AP)?

It is the 2019 AIAG-VDA handbook criterion that replaced RPN. It weights severity more: a mode with S = 9, O = 4 and D = 3 has an RPN of only 108 but high AP, while S = 8, O = 5 and D = 6 has RPN 240 and medium AP.

Can RPN still be used?

Yes, as supporting information, but the AIAG-VDA handbook does not recommend RPN thresholds (such as 100) to decide on actions. Use AP to set the order and RPN to track the reduction.

When should S, O and D be reassessed?

After the action is implemented and verified. Occurrence and detection drop with better prevention and detection controls; severity only changes if the design changes the effect.