A Clustering Search Metaheuristic for the Bi-objective Flexible Job Shop Scheduling Problem

The Flexible Job Shop Scheduling Problem (FJSP) is an extension of Job Shop Scheduling (JSP), which is closer to reality, allowing an operation of a given job to be processed by alternative machines. Considering that for some industries it is relevant to consider for more than one objective, the FJSP is treated in this study in a multiobjective way whit the following criteria: the last processing time of the last operation, called makespan, and the total tardiness. Therefore, it is proposed an algorithm based on the Clustering Search (CS) metaheuristic to generate solutions, and thus produce a set of non-dominated solutions in order to obtain the Pareto frontier, providing to decision maker a set of quality solutions. To evaluate the CS, we proposed a set of instances considering due dates for the jobs, to enable analysis of the bi-objective FJSP (BOFJSP). The CS results were competitive when compared to the literature, generating several non-dominated solutions.