Joint Optimization on Preventive Maintenance and Operating Unit Number for Multi-unit Parallel Production System with One Repairman and Spare Unit

Abstract

Multi-unit parallel production system exists extensively in most enterprises, one repairman and spare unit are always matched to ensure the normal operation of the production system. However, it is a vital issue to optimize the preventive maintenance (PM) policy and operating unit number under the above condition. To this end, the paper oriented the multi-unit parallel production system and developed an optimization model that jointly considered the PM policy and the operating unit number. In the model, the spare unit is placed in an operational state during the period that one of the operating unit is preventively maintained. Then, a numerical example and some parameter sensitive analysises are also given to illustrate the proposed model. Results show the existence of the optimal results via minimizing the system long-running cost rate, indicate that a loss rate of the down time plays an important role for the optimal results and an optimal PM time exists which can minimize the system long-running cost rate.