Common Cause Failure

From CIPedia
Revision as of 13:13, 23 July 2015 by Mtheocharidou (talk | contribs) (Text replacement - "Geographical dependency" to "Geographical Dependency")
Jump to navigation Jump to search

A common cause failure (CCF) - also refered to as Common Mode Failure - is a failure where:

  • The function of multiple CI is disrupted or destroyed by the same cause or hazard affecting the CI at the same location or area in the same time frame (e.g., a hurricane blocking roads and affecting telecommunication and power lines; a collapsed bridge which blocks inland shipping, road transport and caused disruption of gas, power and telecommunication lines)
  • Item failures result from a single shared cause and coupling factor (or mechanism)


Definitions

National Definitions

Australia

Common mode failure is the coincident failure of two or more independent components as the result of a single cause; of particular concern in an instrument system incorporating redundancy where an event causes coincident failure of two or more of the normally independent channels. [1]


International Definitions

IAEA

Common cause failure is the failure of two or more structures, systems or components due to a single event or cause. [2]


Common mode failure is the failure of two or more structures, systems or components in the same manner or mode due to a single event or cause. [2]


Standard Definition

Discussion Topic

See also

Notes

References