scope:

This Standard establishes uniform requirements and criteria for a capability-based Product Failure Mode, Effects and Criticality Analysis (FMECA). The capability-based aspect of this Standard requires that the organization's FMECA capability be rated according to defined criteria for process capability and data maturity. The structured process that this Standard defines integrates the FMECA process with other mission assurance processes within systems engineering to identify, analyze, and manage failure mode risks in a manner which is commensurate with the product's unit-value/safety-impact and systems engineering life cycle phase. Also, it facilitates integrating FMECA data across different enterprises

Purpose

The primary purpose of the Product FMECA is to collect and evaluate the necessary product design information to identify and eliminate or control, but not be limited to, all failure modes that pose unacceptable risk to system safety or mission success. Depending on how it is performed, the FMECA can be used for several different purposes, but its most important use in systems engineering is to aid the improvement of design safety or design reliability before the product design is solidified or product is manufactured. The capability-based FMECA is a set of activities that address product failure or mishap risk at one or more defined capability levels.

A failure mode is the consequence of the mechanism through which the failure occurs, i.e., the manner by which the failure is observed. Accordingly, a failure mode that poses unacceptable risk is a failure mode whose effect, either singularly or in combination with other failure mode effects, violates a product design requirement or goal. The FMECA is a systematic methodology that is widely used to evaluate the effects on systems and interfaces caused by the failure modes of functional, physical, or logical components. It supports estimating the criticality or risk of each failure mode in terms of its end-effects, and evaluates the appropriate failure compensation methods for safety-critical, mission-critical, and maintenance-critical failure modes. The Product FMECA shall comprise the following three components:

• Failure Mode and Effects Analysis (FMEA),
• Criticality Analysis (CA), and Detectability Analysis for repairable products
• Critical Item (CI) Analysis and Failure Compensation (FC) Analysis

The FMEA answers system failure questions regarding the what's, how's, where's, when's, and why's. The CA and the detectability analysis answer system failure questions regarding relative significance. The CI analysis and the FC analysis answer system failure questions regarding failure mitigation. The minimum activities that constitute the baseline practice for the Product FMECA are the following:

• establishment of the requirements and analytical ground-rules for the Product FMECA;
• establishment of Product FMECA Technical Performance Metrics (TPMs);
• collection and evaluation of the necessary product design information to identify and evaluate, but not be limited to, all failure modes that pose unacceptable risk across the product life cycle;
• selection and approval of a single FMECA worksheet format for the entire project, including the subcontractors and suppliers (this activity facilitates integrating the FMECA data across different enterprises);
• identification and documentation of the product's failure modes, failure effects, and failure mechanisms, root causes, or hazards, as required, based on failure mode models obtained or developed for each functional or physical element in the product;
• identification of product design features and operational activities that reduce the likelihood or manage the effects of failure modes;
• calculation of a quantified Criticality Number (Cm) for each failure mode;
• development of a qualified or a quantified detection success probability for each failure mode of a repairable system;
• application of Critical Item (CI) selection criteria and evaluation of failure mode mitigation approaches for each CI;
• development, documentation, and distribution of the Product FMECA Report

The elements of failure mode identification are shown in Figure 1 and the elements of failure probability estimation are shown in Figure 2. These elements shall be included in the FMECA process as required.