Functional failure

Decision Type:

Method Category:

Categories: Terms

Failure of an item to perform its normal or characteristic actions within specified limits.

Complex item
An item whose functional failure can result from any one of numerous failure modes.
Condition-monitoring process
In current regulatory usage, a maintenance process characterized by the absence of scheduled-maintenance tasks. Items (including those with hidden functions) remain in service until a functional failure occurs, and analysis and surveillance programs monitor their overall reliability.
Consequences of failure
The results of a given functional failure at the equipment level and for the operating organization, classified in RCM analysis as safety consequences, operational consequences, nonoperational consequences, and hidden-failure consequences.
Cost effectiveness
Referring to a favorable cost-benefit ratio; the criterion of task effectiveness in preventing any functional failure that has economic, but not safety, consequences (see effectiveness criterion).
Economic consequences
The only consequences of a functional failure, which is evident to the operating organization and has no direct effect on operating safety.