Investigation into skill leveled operators in a multi-period cellular manufacturing system with the existence of multi-functional machines

Abstract

Numerous studies published in the field of cellular manufacturing system are based on the assumption that machines are reliable in the entire production line without any breakdown. Since such assumptions are not usually realistic, to contribute to closing this gap between assumption and reality, a new model was proposed that additionally considered machine reliability, alternative process routings, and workforce assignment in a dynamic environment. Given such considerations in this research, the modified problem was defined and formulated and an extended mixed integer multi-period mathematical model was proposed. In order to evaluate the effectiveness and capability of the extended model, some hypothetical numerical instances were generated and computational experiments were carried out using GAMS optimization package. Experimental results demonstrated that the demand value could affect the machine breakdown rate, and a machine with a minimum breakdown rate was implemented more often than others. Moreover, the observed tradeo ff between the workforce-related costs and cell-formation costs indicated that workforcerelated issues had a significant impact on the total efficiency of the system. The proposed model can be quite applicable to medium- and large-scale manufacturing companies.