Buyer-Vendor Joint Economic Production Inventory Model for Profit Optimization

This study develops a joint economic production–inventory model aimed at maximizing profit by realistically capturing interactions between buyer - vendor. In the proposed framework, both buyer and vendor collaboratively participate in the production process and share responsibility for system performance. The optimal system cost is determined under the assumption of equal profit sharing between the buyer and vendor. Additionally, the model incorporates a quantity discount scheme offered by vendor to buyer when the order quantity exceeds a specified level. Numerical illustrations are provided to demonstrate the applicability of the model and to confirm its effectiveness.