Failure mode and effects analysis (FMEA)

A Failure mode and effects analysis (FMEA) is a procedure for analysis of potential failure modes within a system for the classification by severity or determination of the failures' effect upon the system. It is widely used in the manufacturing industries in various phases of the product life cycle and is now increasingly finding use in the service industry as well. Failure causes are any errors or defects in process, design, or item especially ones that affect the customer, and can be potential or actual. Effects analysis refers to studying the consequences of those failures.

Basic terms
Failure mode: "The manner by which a failure is observed; it generally describes the way the failure occurs."
Failure effect: The immediate consequences a failure has on the operation, function or functionality, or status of some item
Indenture levels: An identifier for item complexity. Complexity increases as the levels get closer to one.
Local effect: The Failure effect as it applies to the item under analysis.
Next higher level effect: The Failure effect as it applies at the next higher indenture level.
End effect: The failure effect at the highest indenture level or total system.
Failure cause: Defects in design, process, quality, or part application, which are the underlying cause of the failure or which initiate a process which leads to failure.
Severity: "The consequences of a failure mode. Severity considers the worst potential consequence of a failure, determined by the degree of injury, property damage, or system damage that could ultimately occur."