Simultaneous control of production, preventive and corrective maintenance rates of a failure-prone manufacturing system

This paper deals with the control of corrective and preventive maintenance rates in the production planning of a manufacturing system with machines subject to random failures and repairs. The introduction of preventive and corrective maintenance will increase the availability of the production system which guarantees the improvement of the system's productivity if the production planning is well done. The objective of this study is to minimize a discounted overall cost consisting of maintenance cost, inventory holding and backlog cost. The decision variables are the production, the machine preventive and repair rates which influence the inventory levels and the system capacity respectively. In the proposed model. the failure rate of a machine depends on its age; hence, the corrective and preventive maintenance policies are machine-age dependent. A computational algorithm, based on numerical methods, is used for solving the optimal control problem. Finally, a numerical example and a sensitive analysis are presented to illustrate the usefulness of the proposed approach. The structure of the optimal control policy is presented and extensions to more complex manufacturing systems are discussed. (c) 2006 IMACS. Published by Elsevier B.V. All rights reserved.