Failure Mode

Any event which causes a failure.  The manner by which a failure is observed, the way the failure occurs. The term refers to the observed way or mechanism of failure.  

For a failure mode to be valid it must answer the question: “What is the primary manner in which the associated failure descriptor becomes evident?”  Depending on the application, the definition of failure mode may slightly vary. 

In a detailed analysis, a failure mode can refer to a physical event / mechanism that gave rise to a failure, such as:

  • Moisture 
  • Corrosion
  • Fatigue
  • Wear.  

Or from a functional point of view, a valve can have several failure modes such as, "fails to operate on demand, valve leakage," etc.  

In a formal reliability-centered maintenance (RCM) program, deeper failure modes are considered as failure causes. Failure modes may also be defined according to the effect by which a failure is observed. 

See also: