Failure Mode and Effects Analysis _FMEA_ Basics by hkksew3563rd


What is a FMEA?

Failure Mode and Effects Analysis (FMEA) or FMECA is an analysis technique
which facilitates the identification of potential problems in a design or process by
examining the effects of lower level failures. Recommended actions or compensating
provisions are made to reduce the likelihood of the problem occurring, and mitigate
the risk, if in fact, it does occur.

The FMEA team determines, by failure mode analysis, the effect of each failure and
identifies single failure points that are critical. It may also rank each failure according
to the criticality of a failure effect and its probability of occurring. FMECA is the
result of two steps: 1) Failure Mode and Effects Analysis (FMEA), and 2) Criticality
Analysis (CA). Or in other words, FMECA is just FMEA with Criticality Analysis.

There are many different types of FMEA. There are Conceptual or Functional FMEAs,
Design FMEAs, and Process FMEAs. Sometimes during a Design FMEA the analysis
will look at a combination of functions and hardware. Sometimes it will include just
hardware, and sometimes the analyst will take a detailed look at the system down to a
piece-part level, especially when critical functions or hardware are involved.

Why is FMEA or FMECA Important?

There are a number of reasons why this analysis technique is so valuable. Here are
just a few:

1) FMEA provides a basis for identifying root failure causes and developing effective
corrective actions.

2) The FMEA identifies reliability and safety critical components.

3) It facilitates investigation of alternatives at all stages of the design or process.

4) FMEA provides a foundation for maintainability, safety, testability, and logistics

FMEA / FMECA Background and History

FMEA or FMECA is an offshoot of Military Procedure MIL-P-1629, titled Procedures
for Performing a Failure Mode, Effects and Criticality Analysis, dated November 9,
1949. It was originally used as a reliability technique to determine the effect of system
and equipment failures. Failures were classified according to their impact on mission
success and personnel/equipment safety.
FMECA was further developed and applied by NASA in the 1960's to improve and
verify reliability of space program hardware. The procedures called out in
MIL-STD-1629A are probably the most widely accepted methods throughout the
military and commercial industry, although SAE J1739 is a very prevalent FMEA
standard used in the automotive industry.


This article just scratches the surface of FMEA, an analysis technique that has proven
its worth time and time again throughout many industries. There are many good books
and other resources where you can find out more about FMEA. Both large and small
companies will benefit as they make FMEA an integral part of their quality programs.

About the Author:

Rich Herman has been involved in reliability engineering for over 20 years and much
of that time has been spent working with FMEA. For more information on FMEA and
FMECA visit his website:

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