Extended inventory planning models for repairable imperfect quality items under withdrawal policies and inspection errors

The repair process is a widely used policy for handling imperfect quality items in inventory systems. However, most prior studies have made unrealistic assumptions, such as assuming all repaired items return to the system and batch withdrawals with infinite withdrawal rates. These assumptions limit the practical applicability of such models. This study addresses these gaps by developing new economic order quantity and economic production quantity models that account for partial repair success, inspection errors, and both finite and infinite withdrawal rates. Additionally, preventive maintenance is integrated into the economic production quantity model. An analytical derivative-based method is employed to determine optimal replenishment policies for four different cases. Numerical results indicate that the total cost is significantly influenced by the demand rate and is sensitive to system parameters. This study contributes to the literature by providing a more realistic approach to inventory and repair systems, offering insights for practical applications.