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Risk Priority Number (RPN)

A score calculated by multiplying severity, occurrence, and detection ratings to prioritise risks in FMEA.

Definition and context

RPN helps teams compare failure modes and decide where to focus improvement resources.

It is a staple output of FMEA analysis sessions used in manufacturing and service industries.

Calculating RPN

Each failure mode receives a severity rating for customer impact, an occurrence rating for likelihood, and a detection rating for control effectiveness.

Multiply the three ratings to obtain RPN. It is a ranking aid, not a measured probability of failure, and identical RPN values can represent different risks.

Using RPN wisely

Teams should look beyond the numeric score to understand underlying risks and consider severity on its own when safety is involved.

High-risk items flow into CAPA plans that assign owners and timelines.

Use the customer-required method. AIAG & VDA FMEA uses Action Priority rather than RPN as its prioritization method.

Where this term fits in the workflow

Risk Priority Number (RPN) is usually shown in the process control and risk.

Terms that help factories monitor variation, validate capability, and reduce risk before defects escape.

What is KaizenQ?

KaizenQ helps factory teams record inspection results, defect photos, and notes in one report shared with the office.

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Key takeaways

  • RPN prioritises failure modes based on severity, occurrence, and detection.
  • Context matters: teams shouldn’t rely on the number alone.

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