Effective techniques of FMEA at each life-cycle stage

The failure mode and effects analysis (FMEA) is a widely used analytical tool, it is especially useful in the conduct of reliability, maintainability, and safety analyses. Such analyses are commonly used to identify failures of significant consequence and those affecting system performance. The author investigated about 100 FMEA applications. That investigation revealed that the FMEA technique is useful in virtually every stage of the modern industrial process. Although FMEAs were most frequently used in the initial design and development stages of a project, they were also of value in the manufacturing stage. In support of manufacturing, FMEAs contributed in deriving the optimum construction method and schedule. Even after construction of the plant, FMEAs were again found to add value in the analyses of day-to-day plant operations and maintenance activities, or the use stage. The continuous application of the FMEA process over the life-cycle of a project is ensured by the preparation of the individual FMEA worksheets for each stage. Examples of such worksheets are presented and discussed in this paper FMEAs are evaluated by either of two methods: criticality or risk priority number (RPN). The criticality method is used primarily at the design, development, and construction stages; whereas, the RPN method is favored at the manufacturing and use stages. The elements which comprise the Criticality and RPN method are also presented in this paper.