Stochastic Modeling of a Single-Unit Repairable System with Preventive Maintenance under Warranty

In this paper a stochastic model for a single unit repairable system with Preventive Maintenance (PM) under warranty is analyzed in details by using supplementary variable technique. The cost of repair during warranty is born by the manufacturers, but warranty does not apply to product failure due to user-induced damage such as cracked screen or cracked casing, accident, misuse, physical damage, damage due to liquid and unauthorized modifications etc. within warranty period. Unit goes under PM during warranty and works as new after PM. There is a single server who always remains with the system. The time to failure of the system follows negative exponential distribution while PM and repair time distributions are taken as arbitrary. The expressions for some economic measures such as reliability, mean time to system failure (MTSF) and availability have been derived. A particular case is considered to highlight the behaviour of reliability and profit function.