FAILURE MODES EFFECTS AND CRITICALITY ANALYSIS, AN UNDERUTILIZED SAFETY, RELIABILITY, PROJECT MANAGEMENT AND SYSTEMS ENGINEERING TOOL

摘要

The majority of space programs whether manned orrnunmanned for science or exploration require that arnFailure Modes Effects and Criticality Analysisrn(FMECA) be performed as part of their safety andrnreliability activities. This comes as no surprise givenrnthat FMECAs have been an integral part of thernreliability engineer’s toolkit since the 1950s. Thernreasons for performing a FMECA are well knownrnincluding fleshing out system single point failures,rnsystem hazards and critical components and functions.rnHowever, in the author’s ten years’ experience as arnspace systems safety and reliability engineer, findingsrndemonstrate that the FMECA is often performed as anrnafterthought, simply to meet contract deliverablernrequirements and is often started long after the systemrnrequirements allocation and preliminary design havernbeen completed. There are also important qualitativernand quantitative components often missing which canrnprovide useful data to all of project stakeholders. Theserninclude; probability of occurrence, probability ofrndetection, time to effect and time to detect and, finally,rnthe Risk Priority Number.rnThis is unfortunate as the FMECA is a powerful systemrndesign tool that when used effectively, can helprnoptimize system function while minimizing the risk ofrnfailure. When performed as early as possible inrnconjunction with writing the top level systemrnrequirements, the FMECA can provide instant feedbackrnon the viability of the requirements while providing arnvaluable sanity check early in the design process. It canrnindicate which areas of the system will requirernredundancy and which areas are inherently the mostrnrisky from the onset. Based on historical and practicalrnexamples, it is this author’s contention that FMECAsrnare an immense source of important information for allrninvolved stakeholders in a given project and can providernseveral benefits including, efficient project managementrnwith respect to cost and schedule, system engineeringrnand requirements management, assembly integrationrnand test (AI&T) and operations if applied early,rnperformed to completion and updated along with systemrndesign.