Production control of failure-prone manufacturing-remanufacturing systems using mixed dedicated and shared facilities

This paper addresses a control problem within hybrid manufacturing-remanufacturing systems (HMRS) evolving in a dynamic and stochastic environment. Unlike previous works, it contributes to the discourse by considering mixed dedicated and shared facilities (MDSF). It is motivated by the need to integrate the remanufacturing flow while increasing the capacity of the system to react to uncertainties (random failures and repairs of facilities, rates of returned products, etc.). The problem is to determine the production rates for the manufacturing and remanufacturing facilities as well as the setup decisions required to switch the remanufacturing facility from a mode supplied by returned products to a mode supplied by raw materials. The objective is to minimize the expected total cost. A dynamic stochastic model is thus proposed, and the developed optimality conditions are solved numerically. The obtained control policy combines hedging point policies and a stock-based setup strategy, under which switching is based on the finished products stock, according to threshold rules. Such control policy is then analyzed and compared to the literature by considering three different control policies. Two of those were developed in other contexts using only dedicated facilities or shared facilities in a dynamic and stochastic environment while the other is adapted to ours. For an effective comparison study, a simulation-based optimization approach is adopted and implemented for the problem under study. Extensive numerical results suggest that the use of MDSF managed by the proposed control policy gives the best performance in terms of costs.