An Optimal Design for an Ordered-entry Array Flexible Assembly System SEYED ALIREZA FEYZBAKHSH*; MASAYUKI MATSUI 1 ** *Department of Management and Systems Sharif University of Technology PO.BOX 11365-8639, Tehran IRAN Abstract: Flexible Assembly Systems (FASs) are finding increasing use in today's industry. An ordered-entry array of unit stations of Generalized CSPSs is designed and studied. The addressed problem is: “given an objective cost function, design a simple FAS to meet the given specifications”. In the proposed two-stage method, minimum cost of each workstation, which is computed independently by Complex-type method at the first stage, has been used in minimizing the objective function at the second stage. Based on the results from an optimization stand-point, the two-stage method seems to produce reasonable engineering results and is superior to the GA optimization method in computational time. Key-words: RIC of Generalized CSPS, Simple Flexible Assembly System, Two-stage Design Method, Optimization via Simulation, Genetic Algorithms. **Department of Systems Engineering,The University of Electro-Communications, Tokyo JAPAN matsui@se.uec.ac.jp