Outage

A discontinuance of electric power supply.

The period during which a generating unit, transmission line, or other facility is out of service. A forced or unplanned outage is the shutdown of a generating unit, transmission line or other facility for emergency reasons. A scheduled or planned outage is the shutdown for inspection or maintenance, in accordance with an advance schedule.

A telecommunications system service condition in which a user is completely deprived of service by the system. Note: For a particular system or a given situation, an outage may be a service condition that is below a defined system operational threshold, i.e., below a threshold of acceptable performance. See outage threshold.