A Study on Integrative Decision-making System for Reconfigurable Manufacturing Cells

Abstract

RMCs (Reconfigurable Manufacturing Cells) are production systems which can rapidly change hardware configurations to respond to market variance. The practical range of such change time is one or two days. In the operation of RMCs, managers encounter two decision problems with regard to how reconfiguring capability of manufacturing systems would be utilized. The first problem is to decide whether and how hardware configurations of manufacturing systems are to be changed. An alternative configuration may improve manufacturing performance in response to demand, but detailed resource allocation needs to be examined together with capacity loss during reconfiguration for accurate evaluation so that managers may make decisions with certainty. However, most of previous studies on hardware reconfiguration dealt it as a tactical problem rather than an operational problem, not providing accurate performance evaluation of manufacturing systems. The second problem is about purchase of equipment. Managers want to know whether their current systems may catch up with future demand or additional equipment needs to be purchased. In this case, reconfiguring capability of manufacturing systems should be considered to satisfy demand with minimized purchasing cost. This study aims to develop an integrative decision-making system for those decision problems. To provide scheduling-level resolution of hardware reconfiguration, a scheduling algorithm appropriate for RMC environment is developed. And using the developed scheduling algorithm, a mathematical model for hardware reconfiguration is presented in consideration with capacity loss during reconfiguration. To solve the model, a relaxation based branch-and-bound algorithm is proposed. Finally, to resolve the equipment purchase problem, an algorithm which minimizes the net-present-value of purchasing cost is suggested.