Risk Priority Number
Risk Priority Number is a numerical value commonly calculated from severity, occurrence, and detection ratings during FMEA.
What this term means in maintenance
Risk Priority Number is a numerical value commonly calculated from severity, occurrence, and detection ratings during FMEA.
Common formula
RPN = Severity × Occurrence × Detection
Practical example
A failure mode has:
- Severity: 8
- Occurrence: 4
- Detection: 5
RPN = 160
Use
RPN helps compare and prioritize failure modes within a controlled assessment method.
Limitations
Different combinations can produce the same RPN even when risk characteristics differ.
High-severity items should not be ignored because occurrence appears low.
Common mistake
Treating one universal RPN threshold as the complete risk decision can hide serious consequences.
Related concepts
Related maintenance terms
Keep exploring connected CMMS, reliability, and maintenance planning terms.
Failure Mode and Effects Analysis
Failure Mode and Effects Analysis, or FMEA, is a structured method for identifying how an asset or process may fail, the effects of each failure, existing controls, and actions needed to reduce risk.
Failure Mode, Effects and Criticality Analysis
Failure Mode, Effects and Criticality Analysis, or FMECA, extends FMEA by adding a more explicit assessment of failure-mode criticality.
Asset Criticality
Asset criticality is a structured assessment of how strongly an asset failure could affect safety, environment, quality, production, compliance, cost, and recovery.
Risk Priority Number FAQs
- What does RPN stand for?
RPN stands for Risk Priority Number.
- How is RPN calculated?
Severity multiplied by occurrence multiplied by detection.
- What is an RPN limitation?
Different risk combinations can produce the same number, and high severity can be hidden.