System Safety for the 21st Century, 2nd Edition

CHAPTER 15Failure Mode and Effects Analysis

Failure mode and effects analysis (FMEA) is one of the better‐known and more widely used systems safety techniques. The FMEA is used in the Department of Defense, NASA, Department of Energy, and private industry programs. Even though different worksheets are used, and it may also be called “Failure Mode and Effect Analysis,” “Failure Modes and Effect Analysis,” or “Failure Modes and Effects Analysis,” the general approach to conducting an FMEA is relatively consistent. Additionally, depending on the organization, reference, or analyst, significant distinctions are sometimes made between an FMEA and a failure mode(s) and effect(s) criticality analysis (FMECA). In some organizations (NASA, for example), a critical items list (CIL) is developed from the FMEA.

In larger organizations where safety, reliability, maintainability, operability, and other factors may be considered separately by specific organizational units, the FMEA is widely recognized as a reliability tool, and rightfully so. The FMEA, by its very nature, specifically determines what can go wrong with each individual piece of hardware and what effects each failure can have. Technically, distinctions are not hard to make among those failures that affect safety, those that affect maintainability, and those that simply affect reliability. As a practical matter, however, most of the time something that breaks or fails to work properly has at least an indirect safety implication. ...