Sequencing Problem in a Paced Mixed-Model Assembly Line with Multiple Flexible Operators

Nowadays, in a highly competitive world market, following the progress of technology and increasing request of personalized production, to meet the diverse demands of customers, traditional mass production needs to move toward customized mass production. Mixed-model assembly line is one of the derivate of production line allowing to apply personalized mass production. In this type of production system, line balancing and sequencing have a brilliant role on enhancing the efficiency of the assembly line. This paper addresses the problem of production sequencing in mixed model assembly line. The goal of is to propose a bi-objective mathematical model to determine the optimal sequence of productions. In this way, two objectives function for minimization of displacement and idle time of operators are proposed. The model is coded in GAMS and CPLEX, allowing the implement of an augmented $\varepsilon$-constraint method to extract Pareto front. The proposed method creates a set of pareto optimal solutions, supporting the decision makers to select the most appropriate solution based on global strategies of companies.