HYBRID MANUFACTURING SYSTEM WITH THREE OPTIONS OF REMANUFACTURED AND DISPOSAL ITEMS

ABSTRACT This study is devoted to the optimal control of a hybrid manufacturing system with returned products after usage, represented as an infant mortality mode under a periodic review policy. Three hybrid models have been discussed; remanufacturing is continuous along the planning period (without a disposal option), remanufacturing happened in the second part of the planning period (disposal happen at arrival), and the remanufacturing rate was constrained by the demand rate (disposal of serviceable products to control inventory). Our contribution to literature was showed in two cases; usage the infant mortality mode to describe returned products, and simplified the optimal control model by using a different approach to achieve constraints. The explicit solution was realized using the Pontryagin maximum principle. Our numerical results suggest that the control of the inventory level satisfies the demands by combining rates of manufacturing and remanufacturing. Also, remanufacturing being continuous along the planning period is better as it minimizes the total cost.