Production/Preventive Maintenance Comprehensive Approach for Manufacturing Systems Susceptible to Quality Degradation

In this study, a combined policy is provided for production control and preventive maintenance for processes that are vulnerable to quality decline. To meet customers demand, production control tackles the issues of production rate regulation and the best size for finished product safety stock. To reduce the number of non-compliant items, plans for preventative maintenance are considered. When the production process begins to make non-compliant parts and is stopped to carry out restoration action, a safety stock is also designed to alleviate shortages. Based on the combined policy, analytical models are provided taking into account all conceivable scenarios and sub-policies that may arise, as well as all possible safety stock level value ranges and the point at which the production processes deviates from the in-control state. To determine the combined optimal policy, a numerical method has been built minimizing the total incurred cost. A simulation program is built, and a sensitivity study is conducted in order to verify and certify the analytical findings and prove the robustness of the proposed approach. The suggested integrated policy is shown to perform better than alternative ones taken into consideration in the literature and in practice by comparison research.