ANP/RPN: a multi criteria evaluation of the Risk Priority Number

TLDR

Failure mode effects and criticality analysis (FMECA) is widely used to assess system failures, yet it traditionally neglects interactions among principal causes. The study proposes an enhanced FMECA that incorporates interactions among principal failure causes. The method integrates FMECA with the Analytic Network Process, structuring severity, occurrence, and detectability into sub‑criteria within a hybrid hierarchy/network, and computes the Risk Priority Number via pairwise comparisons that blend qualitative judgments with quantitative data. Pairwise comparisons simplify design and maintenance decisions, and a case study demonstrates the approach’s robustness and comprehensive criticality analysis. © 2011 John Wiley and Sons Ltd.

Abstract

Abstract This paper presents an advanced version of the failure mode effects and criticality analysis (FMECA), whose capabilities are enhanced; in that the criticality assessment takes into account possible interactions among the principal causes of failure. This is obtained by integrating FMECA and Analytic Network Process, a multi‐criteria decision making technique. Severity, Occurrence and Detectability are split into sub‐criteria and arranged in a hybrid (hierarchy/network) decision‐structure that, at the lowest level, contains the causes of failure. Starting from this decision‐structure, the Risk Priority Number is computed making pairwise comparisons, so that qualitative judgements and reliable quantitative data can be easily included in the analysis, without using vague and unreliable linguistic conversion tables. Pairwise comparison also facilitates the effort of the design/maintenance team, since it is easier to place comparative rather than absolute judgments, to quantify the importance of the causes of failure. In order to clarify and to make evident the rational of the final results, a graphical tool, similar to the House of Quality, is also presented. At the end of the paper, a case study, which confirms the quality of the approach and shows its capability to perform robust and comprehensive criticality analyses, is reported. Copyright © 2011 John Wiley and Sons Ltd.