Reliability

Ability to perform as required, without failure, for a given time interval, under given conditions Note 1 to entry: The reliability of an item can be calculated from the observed failures of it or/and a set of comparable items during a given time interval. Note 2 to entry: The forecasted reliability of an item expresses the level of confidence on it, estimated from the observed reliability of comparable items and the knowledge about its actual state. Note 3 to entry: In some cases, a given number of unit of use can be considered instead of a given time interval (number of cycles, number of running hours, number of km, etc.). Note 4 to entry: The given conditions may include preventive maintenance (3.1.2.15) actions and operational modes and conditions.