Migrating birds optimization with a diversified mechanism for blocking flow shops to minimize idle and blocking time

Blocking flow shop scheduling problem widely exists in industrial processes, and most attention has focused on minimization of economic indicators, such as makespan, total flow time, and due-date-based functions, rather than energy-efficient indicators. This paper considers idle and blocking time criterion, which is closely related to machine energy consumption in blocking flow shops, and proposes a migrating birds optimization with a diversified mechanism (dMBO) for the problem. On the basis of the profile fitting (PF) heuristic and the characteristics of the idle and blocking time, an improved heuristic, named PFI, is proposed by modifying the PF and performing an insert procedure. A best insert operator and an insert-based local search are hybridized in the proposed migrating birds optimization algorithm to enhance its exploitation capability. In order to maintain the diversity of the flock in the algorithm, a diversified mechanism containing three tabu lists and one candidate pool is designed. Extensive computational results validate the effectiveness of the proposed PFI heuristic, and a statistical analysis of the computational results confirms the superiority of the dMBO over several other high-performing metaheuristics. (C) 2021 Elsevier B.V. All rights reserved.