Fault

In document ISO/CD 10303-226 fault is defined as an abnormal condition or defect at the component, equipment, or sub-system level which may lead to a failure.

In telecommunication, the term fault has the following meanings:

1. An accidental condition that causes a functional unit to fail to perform its required function.

2. A defect that causes a reproducible or catastrophic malfunction.

Note: A malfunction is considered reproducible if it occurs consistently under the same circumstances.

3. In power systems, an unintentional short-circuit, or partial short-circuit, between energized conductors or between an energized conductor and ground.

Source: from Federal Standard 1037C and from MIL-STD-188