Inventory Control in Hybrid Manufacturing/Remanufacturing Systems with Fuzzy Demand and Return

Two fuzzy models for inventory control in hybrid manufacturing/remanufacturing systems were developed on the basis of the assumption that the demand rate and the return rate are characterized by triangular fuzzy numbers. The signed distance method is employed to derive the estimate of total cost per unit time. In addition, simple modifications of calculated lot sizes were proposed to make the number of lot sizes be a positive integer. Finally, the validity of the models is demonstrated by a numerical example.