TIME-DEPENDENT UNAVAILABILITY ANALYSIS OF STANDBY COMPONENTS INCORPORATING ARBITRARY FAILURE DISTRIBUTIONS AND 3 INSPECTION MAINTENANCE POLICIES

Standby components suffer a certain type of faults defined as 'unrevealed' faults. For this purpose, they must be, periodically tested to insure their availability for use when needed. The paper presents an effective computational methodology for the time dependent unavailability analysis of standby components. The methodology consists of a set of recursive equations which have been developed assuming an arbitrary probability distribution for component lifetime and considering three commonly used inspection/maintenance policies. This set of equations has a general form and incorporates practical operating features of standby redundant systems. The indices evaluated are the exact point, interval and average unavailabilities for each component under consideration. An availability analysis of standby systems with multiple components can also be conducted by allowing staggered inspection of different sets of components within the same system to be handled by the methodology. Finally, a typical standby system is analyzed for various case studies.