Increasing importance of maintenance has resulted in interest in development and implementation of optimal maintenance strategies in order to improve reliability of systems. This will lead in failure prevention and cost reduction of maintenance systems. When competition in the market increases, the need for high quality products, rapid delivery, and competitive prices will also increase and then industries try to achieve new features in their production systems including automation, integration, and flexibility. This has a direct impact on the needs of industries to high level efficiency. Maintenance operations have become increasingly important due to their important role in keeping and improving product quality, safety issues, spare part availability, production line-off costs, etc. Appropriate maintenance scheduling directly affects the performance of the factory. Traditionally maintenance activities can be justify; MARGIN: 0cm 0cm 0pt; unicode-bidi: embed; DIRECTION: ltr" One of the most applicable maintenance policies is preventive maintenance and preventive replacement of parts before failure occurrence is one of the preventive maintenance activities. Different models have been proposed in the field of preventive maintenance planning for finding optimal age replacement policies. While previous studies have focused mainly on left; MARGIN: 0cm 0cm 0pt; unicode-bidi: embed; DIRECTION: ltr" align=left Keywords: Preventive replacement, Spare part supply, Multiple criteria decision making, Goal programming
