Multi-objective modeling for preventive maintenance scheduling in a multiple production line

The change of market and the explosion of product variety have led to increased automation and the need for complex equipment. Therefore, the reliability and the maintainability of the equipment play an important role in controlling both the quantity and quality of the products. In order to ensure specified availability and reliability of production process, preventive maintenance (PM) should be taken during production process. However, taking unscheduled PM can impose high costs to the firm, and adversely decrease the reliability of production line. In this paper, a multi-objective PM scheduling problem in a multiple production line is considered. Reliability of production lines, costs of maintaining, failure and downtime of system are measured as multiple objectives, and different thresholds for available manpower, spare part inventory and periods under maintenance is applied. Production system in this paper consists of serial and parallel machines. Finally, a test problem has been solved to show the effectiveness of the proposed model.