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

Many works published in the area of cellular manufacturing system are based on the assumption that machines are reliable in the whole production horizon without any break down. As such assumptions often are not realistic, to contribute to closing this gap to reality, the model has been modified by additionally including machine reliability, alternative process routings and workforce assignment in a dynamic environment. In this research to integrate this aspects, the modified problem has been defined and formulated and an extended mixed integer multi-period mathematical model has been proposed. In order to evaluate the effectiveness and capability of the extended model, some hypothetical numerical instances are generated and computational experiment are carried out using Gams optimization package. Experimental results demonstrate that the demand value can affect the machine breakdown rate, and a machine with a minimum breakdown rate is implemented more often than others. Moreover, the observed trade-off between the workforce-related costs and the cell-formation costs indicates that workforce-related issues have a significant impact on the total efficiency of the system. The proposed model can be implemented in medium- and large-scale manufacturing companies.