A production scheduling problem with sequence-dependent changeover costs

This paper presents a novel three-step heuristic algorithm which assigns products to parallel heterogeneous machines and determines the sequence in which the products are run on each machine. The objective is to minimise the total set-up cost, which is sequence-dependent. In the algorithm's first step, products are assigned to machines while evaluating each potential assignment's impact on the tentative sequence. In the second step, an optimal sequence is determined given the assignment from the first step; this is done using a dynamic constraint-generation method. The third step improves the solution through a local search heuristic. The developed algorithm is very efficient in solving large problems and has been implemented at the corresponding author's organisation.