FLC-archive to solve multiobjective reentrant hybride flowshop scheduling problem

Abstract

This article deals with the multiobjective reentrant hybrid flowshop scheduling problem. In the latter several tasks has to be processed in a system and the special feature here is that they must be processed several times on each machines. The system is composed of multiple stages which contain parallel identical machines. Since the tasks must reenter the system at the end of the normal process they create conflict with the following tasks. This problem is NP-Hard and we have developped a metaheuristics to solve it. The latter is an evolutionary algorithm based on the well known SPEA2 mechanism. This algorithm has a Fuzzy-Logic Controller to adapt mutation and crossover probability of generation t with respect to the structure of the population in previous generations (t −1) and (t −2). The two objectives are the makespan and the total tardiness minimization. In this works we compare the classic SPEA2 and the latter improved by FLC (so called FLC-archive). These two algorithms are tested on multiple instances adapted from the literature. Finally the comparisons of the results obtained by the algorithms are done with two different multi-objectives measures.