A novel discrete harmony search algorithm for scheduling lot-streaming flow shops

This paper proposes a novel discrete harmony search (DHS) algorithm to minimize makespan for a lot-streaming flow shop scheduling problem with sequence dependent setup times. Unlike the traditional harmony search (HS) algorithm, the proposed DHS algorithm utilizes job permutations to represent harmonies and applies a job-permutation-based improvisation to generate new harmonies. To enhance the algorithm´s searching ability, an effective initialization scheme based on the NEH heuristic is developed to construct an initial harmony memory with certain quality and diversity, and an efficient local search algorithm based on the insert neighborhood structures is fused to stress the local exploitation. Extensive computational simulations and comparisons are provided, which demonstrate the effectiveness of the proposed DHS against the best performing algorithms from the literature.