OPTIMAL PREVENTIVE MAINTENANCE POLICIES IN AN M/G/1 QUEUE-LIKE PRODUCTION SYSTEM

This paper considers the maintenance of an unreliable M/G/1 queue-like production system. Using arguments from renewal theory, basic results of the maintenance policy are established. Furthermore, some inferences are drawn regarding the design of maintenance policy when both the quality and quantity issues in a production system are considered. The results indicate that the optimal maintenance policv is very sensitive to the monitoring technology adopted by the production system. If the system does not have a good monitoring technology, then preventive maintenance operations are very important to the production system. On the other hand, if the system has a good monitoring technology, it may be optimal to conduct only repair (unscheduled) maintenance operations. The results also indicate that if the system is too unreliable (i.e., the probability of switching from an in-control to an out-of-control state is high), then irrespective of the maintenance policy used, the system will always incur a loss. Thus, it is best not to operate the system.