Failure Modes and Effects Analysis (FMEA) and variants

Failure Modes and Effects Analysis (FMEA) is a form of consequence analysis that can be used both for hazard identification and risk analysis, usually performed early in the safety life cycle and may be expanded upon later.

The system is split into subsystems and each of the failure modes of each subsystem is looked at in turn, performing consequence analysis by looking at the local and system effects of each failure mode.

Various extensions and similar methods exist, such as Failure Modes Effects and Criticality Analysis (FMECA) (where the criticality of the consequence is also considered) and Functional Failure Analysis (FFA) (where the focus is on the system failures).

As with Hazard and Operability (HAZOP) studies, although a FMEA can be thorough, it can suffer from both repetitiveness and poor choice of subsystems.


Although officially outdated, MIL-STD-1629 "Procedures for Performing a Failure Mode, Effects and Criticality Analysis" remains a widely used resource.


Although many organisations have considerable with FMEA, it is important to use it both efficiently and effectively within a system safety program, in particular the overlap with any Reliability, Availability and Maintainability (RAM) program.