A MODEL FOR THE MINIMUM-COST CONFIGURATION PROBLEM IN FLEXIBLE MANUFACTURING SYSTEMS

This paper presents a mathematical programming model to help select eq uipment for a flexible manufacturing system, i.e., the selection of th e types and numbers of CNC machines, washing stations, load/unload sta tions, transportation vehicles, and pallets. The objective is to minim ize equipment costs and work-in-process inventory cost, while fulfilli ng production requirements for an average period. Queueing aspects and part flow interactions are considered with the help of a Jacksonian-t ype closed queueing network model in order to evaluate the system's pe rformance. Since the related decision problem of our model can be show n to be NP-complete, the proposed solution procedure is based on impli cit enumeration. Four bounds are provided, two lower and two upper bou nds. A tight lower bound is obtained by linearizing the model through the application of asymptotic bound analysis. Furthermore, asymptotic bound analysis allows the calculation of a lower bound for the number of pallets in the system. The first upper bound is given by the best f easible solution and the second is based on the anti-starshaped form o f the throughput function.