Joint optimization strategy based on a three-state manufacturing system considering dynamic buffers

This paper investigates the joint optimization problem for imperfect manufacturing systems with two production states (controlled and uncontrolled) and one failure state. To simultaneously optimize the quality, maintenance, and production strategies, researchers typically employ a fixed buffer stocking time. However, this approach can lead to excessive holding costs or stockouts. Therefore, we formulate a dynamic buffer replenishment problem in which the buffer replenishment time is treated as a variable that adjusts according to the actual production conditions. Additionally, we consider the effect of the defect rate in the uncontrolled state, where there is a probability of producing defective products; this allows for the real-time detection of uncontrolled systems. Then, we present a new joint control model constructed to derive optimal production, maintenance, and quality strategies by minimizing the expected average cost per unit of time. We use a numerical example to evaluate the proposed model, and the numerical results show that our strategy is more cost-effective than the model with a fixed buffer time that does not consider the quality strategy. The results indicate that the proposed model is more realistic than existing models and can help companies achieve higher profits.