FMEA or FMECA Jargon
The definitions of the terms are given below can be considered as the fundamentals of FMEA/FMECAs. These definitions will enable the reader to understand the differences between Part Function, Failure Detection, Failure Effect, Part Failure Mechanism, and Failure Modes. (These definitions were taken though MIL-STD-1629.)
It is the manner by which a failure is observed. Generally it is the way the failure occurs and its impact on equipment operation.
It is the consequence(s) of a failure mode on the, function, operation or status of an item. Usually, failure effects are classified according to how the entire system is impacted.
The physical or chemical process, design defects, quality defects, part misapplication, or other processes that are the basic reason for failure or which initiate the physical process by which deterioration processes to failure.
The conditions, influences, circumstances stresses and combinations thereof, surrounding and affecting systems or equipment during storage, handling, transportation, testing, installation, and use in standby status and operations.
The means or method by which a failure can be seek by an operator under normal system operation or can be discovered by the maintenance crew by some diagnostic action.
Severity is the worst potential consequence of a failure, determined by the degree of injury, property damage, or system damage that could ultimately occur.
It is a relative measure of the consequences of a failure mode and its frequency of occurrence.
- Criticality Analysis (CA)
A procedure by which each of potential failure modes is ranked according to the combined influence of severity and probability of occurrence is known as Criticality Analysis.