Dynamic Scheduling Using the Mixture of a Genetic Algorithm and a Priority Rule (The Effect of Priority Rule with Consideration to the Due-Date Allowance)

Abstract

We have proposed a dynamic scheduling method using the mixture of a genetic algorithm and a priority rule. In the method, a dynamic scheduling problem is assumed to be a series of static problems and scheduled on a rolling basis. In this paper, we examine the effect of priority rule used in the method. For this purpose, two types of the ATC rules having two parameters are used. The first type is the rule whose parameters are tuned for the dynamic scheduling environment. The second type is the rule whose parameters are tuned for the imminent static scheduling problem. Numerical experiments show the followings : The proposed scheduling method searches effective schedules guided by the priority rule and the rule has important effect to the scheduling performance. For the dynamic job shop scheduling, the scheduling method using the first type of ATC rule greatly outperforms the one using the second type of ATC rule. The reason can be explained by considering the due-date allowance contained in the optimized schedules.