Fail-safe

In engineering, a fail-safe is a design feature or practice that, in the event of a failure of the design feature, inherently responds in a way that will cause minimal or no harm to other equipment, to the environment or to people. Unlike inherent safety to a particular hazard, a system being "fail-safe" does not mean that failure is naturally inconsequential, but rather that the system's design prevents or mitigates unsafe consequences of the system's failure. If and when a "fail-safe" system fails, it remains at least as safe as it was before the failure.[1][2] Since many types of failure are possible, failure mode and effects analysis is used to examine failure situations and recommend safety design and procedures.[3]

Some systems can never be made fail-safe, as continuous availability is needed. Redundancy, fault tolerance, or contingency plans are used for these situations (e.g. multiple independently controlled and fuel-fed engines).[4]

  1. ^ "Fail-safe". AudioEnglich.net. Accessed 2009.12.31
  2. ^ e.g., David B. Rutherford Jr., What Do You Mean It\'s Fail Safe? . 1990 Rapid Transit Conference
  3. ^ Force V: The history of Britain's airborne deterrent, by Andrew Brookes. Jane's Publishing Co Ltd; First Edition 1 Jan. 1982, ISBN 0710602383, p.144.
  4. ^ Bornschlegl, Susanne (2012). Ready for SIL 4: Modular Computers for Safety-Critical Mobile Applications. MEN Mikro Elektronik. Archived from the original (pdf) on 2019-06-09. Retrieved 2015-09-21.