What is Failure mode, effects and criticality analysis (FMECA)

What is Failure mode, effects and criticality analysis (FMECA)

Failure mode, effects and criticality analysis (FMECA) is an extension of failure mode and effects analysis (FMEA).

FMEA is a bottom-up, inductive analytical method which may be performed at either the functional or piece-part level. FMECA extends FMEA by including a criticality analysis, which is used to chart the probability of failure modes against the severity of their consequences. The result highlights failure modes with relatively high probability and severity of consequences, allowing remedial effort to be directed where it will produce the greatest value. FMECA tends to be preferred over FMEA in space and North Atlantic Treaty Organization (NATO) military applications, while various forms of FMEA predominate in other industries.


What is Failure Mode and Effect Analysis ( FMEA )

FMECA analysis procedure


The FMECA analysis procedure typically consists of the following logical steps:

  • Define the system
  • Define ground rules and assumptions in order to help drive the design
  • Construct system block diagrams
  • Identify failure modes (piece-part level or functional)
  • Analyze failure effects/causes
  • Feed results back into design process
  • Classify the failure effects by severity
  • Perform criticality calculations
  • Rank failure mode criticality
  • Determine critical items
  • Feed results back into design process
  • Identify the means of failure detection, isolation and compensation
  • Perform maintainability analysis
  • Document the analysis, summarize uncorrectable design areas, identify special controls necessary to reduce failure risk
  • Make recommendations
  • Follow up on corrective action implementation/effectiveness

Failure effects analysis

Failure effects are determined and entered for each row of the FMECA matrix, considering the criteria identified in the ground rules. Effects are separately described for the local, next higher, and end (system) levels. System level effects may include:

  • System failure
  • Degraded operation
  • System status failure
  • No immediate effect

The failure effect categories used at various hierarchical levels are tailored by the analyst using engineering judgment.

FMECA report

A FMECA report consists of system description, ground rules and assumptions, conclusions and recommendations, corrective actions to be tracked, and the attached FMECA matrix which may be in spreadsheet, worksheet, or database form.


Sachin Thorat

Sachin is a B-TECH graduate in Mechanical Engineering from a reputed Engineering college. Currently, he is working in the sheet metal industry as a designer. Additionally, he has interested in Product Design, Animation, and Project design. He also likes to write articles related to the mechanical engineering field and tries to motivate other mechanical engineering students by his innovative project ideas, design, models and videos.

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