An Enhanced Greedy Random Adaptive Search Procedure with Path-Relinking for No-Wait Flowshop Problem with Setup Times

In this paper, we consider the no-wait flowshop scheduling problem with sequence-dependent setup times to minimize makespan, which is widespread in industries. An enhanced greedy random adaptive search procedure is combined with the Path-Relinking and the GRPEP method is proposed for the problem under study. An evolutionary local search algorithm is integrated to improve the exploration of the search process. Two local search methods, with and without memory, are introduced to improve the intensification. An ageing strategy is developed to increase the diversification. The proposed algorithm is compared with existing approaches for the considered problem and some recent effective algorithms for flowshop scheduling problems with sequence-dependent setup times on benchmark instances. Experimental results show that GRPEP outperforms all the compared meta-heuristics with the same CPU-times. GRPEP obtains better solutions than the compared heuristics