Product Design, Manufacturing & Innovation Resources
Home » Failure Mode, Effects, and Criticality Analysis (FMECA)

Failure Mode, Effects, and Criticality Analysis (FMECA)

1980
  • United States Military
Military engineer analyzing FMECA chart in 1980s workspace for reliability assessment.

(generated image for illustration only)

FMECA is an extension of FMEA that includes a criticality analysis, which charts the probability of failure modes against the severity of their consequences. This allows for a quantitative ranking of failure modes based on the combined influence of their severity and probability. The result highlights single points of failure and helps prioritize corrective actions based on a more rigorous risk level.

FMECA enhances the qualitative aspects of FMEA by introducing a quantitative criticality assessment, as defined in standards like MIL-STD-1629A. Criticality is typically calculated in two ways: modal criticality and item criticality. Modal criticality is calculated for each failure mode and can be expressed as \(C_m = lambda_p alpha beta K_e\), where \(lambda_p\) is the part failure rate, \(alpha\) is the failure mode ratio (the fraction of part failures attributable to this mode), \(beta\) is the conditional probability that the failure effect will result, and \(K_e\) is the severity factor. Item criticality is then the sum of the modal criticalities for all failure modes of a particular item.

This quantitative approach is particularly valuable in high-risk industries like aerospace, defense, and nuclear power, where a more granular and defensible method than the standard RPN is required. The output is often a criticality matrix, which plots severity categories against probability of occurrence levels. This matrix provides a clear visual representation of the highest-risk items, allowing engineers and managers to focus resources on mitigating the most critical potential failures, especially those that could lead to catastrophic system loss or loss of life.

UNESCO Nomenclature: 3313
– Systems design

Type

Abstract System

Disruption

Substantial

Usage

Niche/Specialized

Precursors

  • failure mode and effects analysis (fmea)
  • fault tree analysis (fta)
  • probabilistic risk assessment (pra)
  • reliability block diagrams

Applications

  • aerospace system safety analysis
  • nuclear power plant risk assessment
  • military hardware reliability
  • offshore oil and gas platform safety
  • medical infusion pump design

Patents:

NA

Potential Innovations Ideas

Due to scrapping bot traffic, currently more than 40k per day, this content is reserved to community members.
> Login < or > Register < (100% free) to access this, so as all other restricted content and tools.

Related to: FMECA, FMEA, criticality analysis, risk assessment, reliability engineering, safety engineering, MIL-std-1629a, quantitative risk, single point of failure, aerospace.

Historical Context

Failure Mode, Effects, and Criticality Analysis (FMECA)

1980
1980
1980
1980
1980
1980
1984
1980
1980
1980
1980
1980
1980
1981
1986

(if date is unknown or not relevant, e.g. "fluid mechanics", a rounded estimation of its notable emergence is provided)

Related Invention, Innovation & Technical Principles

Full size images and downloads are only available, 100% free, for registered members.

> Login <