FMEA RPN and Action Priority Tool

Tool

Enter failure modes and ratings

Core formula: RPN = Severity x Occurrence x Detection

Priority method Classic S/O/D entry AIAG/VDA-style Action Priority

FMEA rows

Use one row per failure mode in the format: `Failure mode, Effect, S, O, D, New S, New O, New D`

Results

Risk summary

Highest RPN: 216
Highest AP: High
Rows Requiring Action: 2
Avg. Before RPN: 151.3
Avg. After RPN: 62.7
Total RPN Reduction: 88.6

Interpretation

Top risk: Seal leak currently carries the strongest action need.

Action Priority note: AIAG/VDA mode emphasizes severity and detection more heavily than simple RPN thresholds.

Mitigation note: the before/after simulator shows how much planned controls can reduce risk exposure before the team closes actions.

Sort note: click any table header below to reorder the full FMEA module by that field.

Thresholds

Recommended action logic

Rows with AP = High or RPN above the working threshold should move to immediate action planning.

Mode summary: Classic mode uses a pragmatic RPN threshold overlay, while AIAG/VDA mode maps the combination to an action priority band.

After-mitigation view: use the recalculated RPN and AP to judge whether additional controls are still required.

Simulator

Before / after effect

Failure Mode	Before RPN	After RPN	Delta
Seal leak	216	72	144

Module

Sortable FMEA table

							Recommended Action	New RPN	New AP
Seal leak	Customer complaint	9	4	6	216	High	Immediate action plan	72	Medium

Instructions

How to use this app

Choose classic S/O/D scoring or AIAG/VDA-style Action Priority mode.
Enter one failure mode per row with current S, O, D and proposed post-mitigation values.
Click `Calculate FMEA` to return RPN, AP, threshold guidance, and before/after deltas.
Use the sortable table to rank the full module by RPN, AP, severity, or any other field.
Review the after-mitigation column to decide whether the proposed action is sufficient or whether more controls are needed.

Classic RPN is still useful for prioritization, but Action Priority gives more weight to high-severity scenarios even when the numeric RPN is not extreme.

The built-in AP logic here is a practical approximation for day-to-day FMEA work. If your customer or plant uses a stricter AIAG/VDA interpretation, align the rules to that local standard.

What This FMEA Calculator Helps You Decide

This tool converts Severity, Occurrence, and Detection ratings into immediate risk logic. It helps teams compare classic RPN scoring with AIAG-VDA-style Action Priority thinking, then test how mitigation changes the before-versus-after risk picture.

That makes it useful during PFMEA workshops, launch reviews, corrective-action follow-up, and control-plan decisions where teams need to move quickly without losing scoring rigor.

Core FMEA Formulas and Logic

Concept	Formula or Logic	Use
RPN	Severity x Occurrence x Detection	Classic numerical ranking of failure risk.
Action Priority	Banding based on S, O, D combination	AIAG-VDA decision logic for high / medium / low action urgency.
Before / after delta	Original RPN - revised RPN	Shows whether the proposed action actually reduces risk.

Worked Example

Suppose a seal leak has Severity 9, Occurrence 4, and Detection 6. The classic RPN is 216, which clearly demands action. If the team upgrades the process control and inspection so the revised scores become 7, 2, and 4, the new RPN becomes 56.

The main question is not whether the number got smaller. The real question is whether the prevention and detection changes are real, assigned, and strong enough to justify the lower rating. This tool makes that comparison visible.

How to Interpret the Results

High Severity: do not let a tolerable occurrence score hide serious customer or safety impact.
High RPN but weak action quality: the number is not the problem; the mitigation strategy is.
High Action Priority: respond quickly even when the raw multiplication does not look extreme.
Small before/after improvement: the proposed controls may not be strong enough.

FMEA Tool Frequently Asked Questions

What is the difference between RPN and Action Priority?

RPN is a multiplication result. Action Priority is a decision framework that gives more weight to severe combinations even when the raw multiplication can be misleading.

Should high severity items always be acted on?

Yes, especially when safety, regulatory, or critical customer function is involved. High severity should trigger disciplined review even if occurrence is low.

Can the same RPN represent different real-world risk?

Yes. Different combinations of Severity, Occurrence, and Detection can produce the same RPN while implying very different action urgency.

What is the best use of the before-after simulator?

Use it to challenge whether a mitigation plan truly lowers occurrence or improves detection, rather than assuming every action deserves a lower score.

What is the most common FMEA scoring mistake?

Scoring by opinion without shared definitions or evidence. Inconsistent scoring weakens every downstream action decision.

Related Templates and Guides

Download the PFMEA Template

Move directly from calculator-level scoring into a full PFMEA worksheet with owners, controls, and rescoring fields.

Read the FMEA Guide

Use the guide when the team needs stronger logic on scoring consistency, mitigation planning, and review cadence.