Tntroducing co-evolution and sub-evolution processes into genetic algorithm for job-shop scheduling

In our recent research, we showed results of the comparative study on effects of using several kinds of scheduling evaluation criteria as the fitness function of a genetic algorithm for job-shop scheduling. From these results, we obtained that the idle time criterion sometimes can provide a good makespan-minimizing schedule for a job-shop scheduling problem. In this paper, according to the above results, we introduce coevolution process in which both makespan and idle time schedule criteria are employed as the fitness functions into the operation-based genetic algorithm for job-shop scheduling. Additionally, to provide high diversity for chromosome population, we introduce a sub-evolution process in which the total job waiting time schedule criterion is used as the fitness function in the proposed genetic algorithm.