Definition(s)


Common-Cause Failure

Failures of different items resulting from the same direct cause, occurring within a relatively short time, where these failures are not consequences of another. NOTE Components that fail due to a shared cause normally fail in the same functional mode. The term common mode is, therefore, sometimes used. It is, however, not considered to be a precise term for communicating the characteristics that describe a common-cause failure.

Source: API STD 2000, Venting Atmospheric and Low-pressure Storage Tanks, Sixth Edition, November 2009. Global Standards

 

Common Cause Failure

Failures of different items resulting from the same direct cause, occurring within a relatively short time, where these failures are not consequences of each other.

Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global Standards

 

Common Cause Failure

failures of different items, resulting from a single event, where these failures are not consequences

of each other

Note 1 to entry: It is generally accepted that the failures occur simultaneously or within a short time of each other.

Note 2 to entry: Common cause failures can lead to common mode failures.

Note 3 to entry: Common cause failures reduce the effect of system redundancy.

Note 4 to entry: Explicit and implicit CCF are defined in 5.4.2.

Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global Standards

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