In FMEA, what does the Risk Priority Number (RPN) represent?

• A. Reliability Prioritization Node; used to sequence tests.
• B. Risk Priority Number; used to prioritize failure modes by multiplying Severity, Occurrence, Detection.
• C. Risk Probability Number; used to compute overall system risk.
• D. Response Performance Normalization; used to calibrate sensors.

Answer: (B)

In FMEA, the Risk Priority Number is the numeric score used to rank and prioritize potential failure modes by combining three factors: how severe the effect would be if the failure occurs, how likely the failure is to occur, and how likely it is that current controls would detect it before it reaches the customer. Each factor is typically rated on a scale (often 1 to 10), and multiplying them gives the RPN. A higher RPN points to a higher-priority risk and guides where to focus mitigation efforts. Keep in mind that RPN is a rough prioritization tool—different combinations can yield the same number, and it doesn’t directly reflect risk after controls are implemented. The other options describe terms not used for this purpose.