Occupational Safety, Health, and Environmental (OSHE) BlogOccupational Safety, Health, and Environmental (OSHE) BlogRisk Priority Number (RPN) Calculator
FMEA Risk Tool
Calculate Risk Priority Numbers for FMEA analysis and risk assessment in process management.What is Risk Priority Number (RPN)?
Risk Priority Number (RPN) is a key metric used in Failure Mode and Effects Analysis (FMEA) to assess the risk level of potential failures in a process, product, or system. It helps prioritize which failure modes require immediate attention and corrective actions.
RPN is calculated by multiplying three factors: Severity (impact of the failure), Occurrence (frequency of the failure), and Detection (ability to detect the failure before it reaches the customer).
RPN Formula
Risk Priority Number =
Severity × Occurrence × Detection
Each factor rated on a scale of 1-10
Rating Scales
Severity (1-10)
1-2:Minor
3-4:Low
5-6:Moderate
7-8:High
9-10:Critical
Occurrence (1-10)
1-2:Very Low
3-4:Low
5-6:Moderate
7-8:High
9-10:Very High
Detection (1-10)
1-2:Very High
3-4:High
5-6:Moderate
7-8:Low
9-10:Very Low
Risk Level Classification
Low Risk≤ 50
Medium Risk51 - 100
High Risk101 - 200
Critical Risk> 200
RPN Calculator
Impact of the failure on the customer/process
Frequency of the failure occurring
Ability to detect the failure before it reaches the customer