A unique fuzzy multi-criteria decision making: computer simulation approach for productive operators' assignment in cellular manufacturing systems with uncertainty and vagueness

In today's competitive world, manufacturing firms require to meet demand, increase quality, and decrease cost due to continuous changes in the market. Because of the importance of flexible manufacturing system, the optimum operator allocation problem in cellular manufacturing systems (CMSs) is a challenging issue. Hence, the aim of this paper is presenting a decision making approach based on Fuzzy Analytical Hierarchy Process (Fuzzy AHP), Technique for Order Performance by Similarity to Ideal Solution (TOPSIS), and computer simulation to determine the most efficient number of operators and the efficient measurement of operator assignment in CMS. Also, the proposed approach is performed by employing the number of operators, average lead time of demand, average waiting time of demand, number of completed parts, operator utilization, and average machine utilization as criteria for decision making. An actual case is considered and a computer simulation which considers various operators layout is developed with respect to the purpose of this study and 36 scenarios is produced. In order to find the best scenarios among 36 alternatives, a combined Fuzzy AHP and TOPSIS is employed. The Fuzzy AHP method is applied to determine the importance weight of the criteria. Finally, the TOPSIS method is utilized to rank and analyze scenarios. Also, a sensitivity analysis is carried out for validating the obtained results.