A Parallel System with Priority to Preventive Maintenance Subject to Maximum Operation and Repair Times

摘要

The main intension of this paper is to determine reliability measures of a parallel system of two identical units under the aspect of priority to preventive maintenance over repair and replacement of the unit. The unit has two modes-operative and complete failure. The operation of at least one unit is sufficient for smooth functioning of the system. A single repair facility is provided immediately to conduct repair activities. The unit undergoes for preventive maintenance after fixed maximum operation time. However, the unit is replaced by new one if its repair is not possible by server in the given maximum repair time ‘t’. Priority is given to preventive maintenance of one unit over repair and replacement of the other unit. The unit works as new after preventive maintenance and repair. The random variables associated with failure, preventive maintenance, repair and replacement times of the unit are statistically independent. The distributions of failure time and the times to which unit undergoes to preventive maintenance and replacement are taken as negative exponential. But, the distributions of preventive maintenance, repair and replacement times are assumed as arbitrary. The semi-Markov process and regenerative point technique are used to derive expressions for system performance measures in steady state. A particular case is considered to depict the graphical behavior of mean time to system failure (MTSF), availability and profit function. The cost benefit analysis of the system model is done under different repair cost policies.