Modified approach for prioritization of failures in a system failure mode and effects analysis

Abstract

Describes a new technique for prioritizing failures for corrective actions in failure mode and effects analysis (FMEA). This technique extends the risk prioritization beyond the conventional risk priority number (RPN) method. A new scale has been defined. The ranks 1 through 1,000 are used to represent the increasing risk of the 1,000 possible severity‐occurrence‐detection combinations, called risk priority ranks (RPRs). The failures having a higher rank are given higher priority. This approach resolves some of the shortcomings in the traditional RPN technique. Traditionally, FMEA identifies the risk associated with a product failure through assignment of a standard RPN. A fundamental problem with FMEA is that it attempts to quantify risk without adequately quantifying the factors that contribute to risk. In particular cases, RPNs can be misleading. This deficiency can be eliminated by using the new technique. A methodology combining the benefits of matrix FMEA and the new technique as stated above is presented.