A novel grouping harmony search algorithm for the no-wait flow shop scheduling problems with total flow time criteria

This paper presents a novel grouping harmony search algorithm for solving the no-wait flow shop scheduling problems with total flow time criteria. Flow-shop scheduling problem (FSSP) is a typical NP-hard combinational optimization. Firstly, the HS optimization mechanism and FSSP is presented and the total flow time is calculated by a novel method. Secondly, a largest-order-value rule is used to transform harmony in harmony memory from real vectors to job sequence so that the harmony search can be applied for FSSP. Thirdly, the main contribution of this study is due to the fact that harmony memory is divided into groups and groups share information reciprocally in the process of optimization. At last, simulations demonstrate the efficiency, effectiveness and robustness of harmony search algorithm for no-wait FSSP with total flow time criteria.