An improved harmony search algorithm for the distributed two machine flow-shop scheduling problem

Abstract

In this paper, an improved harmony search (IHS) algorithm is proposed to solve the distributed two machine flow-shop scheduling problem (DTMFSP) with makespan criterion. First, a two-stage decoding rule is developed for the decimal vector based representation. At the first stage, a job-to-factory assignment method is designed to transform a continuous harmony vector to a factory assignment. At the second stage, the Johnson’s method is applied to provide a job sequence in each factory. Second, a new pitch adjustment rule is developed to adjust factory assignment effectively. The influence of parameter setting on the IHS is investigated based on the Taguchi method of design of experiments, and numerical experiments are carried out. The comparisons with the global-best harmony search and the original harmony search demonstrate the effectiveness of the IHS in solving the DTMFSP.