Engineering tool
FMEA risk priority number calculator
Calculate RPN for failure modes and rank them, with severity treated as a priority in its own right.
Inputs
| Failure mode | S | O | D | RPN |
|---|
Result
Enable JavaScript to use this calculator. The method and formulas are explained below.
Formula
RPN = Severity × Occurrence × Detection (each 1 to 10)
Important limitation
The harmonised AIAG and VDA FMEA Handbook replaced RPN with Action Priority (AP) tables, because equal RPN values can represent very different risks. High severity failure modes deserve attention even with low RPN. Use this tool for education and legacy FMEAs; follow your customer's FMEA method for official work. See FMEA.
Use of this toolThis calculator is an educational aid. It is not a substitute for the governing standard, the customer specification or engineering approval. Verify results before using them for acceptance decisions.