This study focuses on simple stationary demand satisfied by the remanufacturing of products and the manufacture of new products. Further, we presented how to use batch processing to reduce defective products in the remanufacturing and the manufacturing inventory. In this paper, we obtain the economic order quantity of new products and the optimal inventory level of products that have been remanufactured as well as the appropriate return rate for the economic order quantity and the economic remanufacturing quantity. We analyze an inventory system with unit product returns and demands wherein manufacturing is the cheaper alternative to remanufacturing. However, because demand exceeds the rate of return of defective products, remanufacturing of products is also required.