Iterative search method for total flowtime minimization no-wait flowshop problem

In this paper, the no-wait flowshop problem with total flowtime minimization is considered. In order to fast evaluate a new solution generated in the searching process in an algorithm, the objective increment properties of fundamental operators are analyzed on the basis of the distance of adjacent jobs in a sequence. An iterative search method is proposed for the considered problem. Two initial solutions are constructed by two investigated heuristics, and assigned as the parent solutions. The parent solutions are improved iteratively by a mini-evolutionary algorithm based on perturbation cycle. Each perturbation cycle consists of a perturb operation and an enhancement process following two strategies: (1) segment-based local search, and (2) iterative global search. The proposed method is compared with the best existing algorithms under the classical benchmark instances. Computational result reveals that the proposed method outperforms the others on effectiveness.