This paper presents a decision making approach based on a hybrid GA for determining the most efficient number of operators and the efficient measurement of operator assignment in cellular manufacturing system (CMS).The objective is to determine the labor assignment in CMS environment with the optimum performance. We use The GA for getting near optimum ranking of the alternative with accordance to fitness function. Also, the GA approach is performed by employing the number of operator, average lead time of demand, average waiting time of demand, number of completed parts, operator utilization and average machine utilization as attributes, and Entropy method for determining the weight of attributes. Furthermore, values of the attributes procured by means of simulation.