%0 Journal Article
%T A Dynamic Genetic Algorithm for Solving a Single Machine Scheduling Problem with Periodic Maintenance
%A Amir Ebrahimy Zade
%A Mohammad Bagher Fakhrzad
%J ISRN Industrial Engineering
%D 2013
%R 10.1155/2013/936814
%X The scheduling problem with nonresumable jobs and maintenance process is considered in order to minimize the makespan under two alternative strategies. The first strategy is to implement the maintenance process on the machine after a predetermined time period and the second one is to consider the maximum number of jobs that can be done with an especial tool. We propose a new mathematical formulation for the aforementioned problem which is included in the NP-Hard class of problems; in the second part of the paper, we propose a dynamic genetic algorithm so that the large- and medium-scale problems could be solvable in computationally reasonable time. Also we compare the performance of the proposed algorithm with existing methods in the literature. Experimental results showed that the proposed genetic algorithm is able to attain optimum solutions in most cases and also corroborate its better performance from the existing heuristic methods in the literature. 1. Introduction and Literature Review In most scheduling problems, it is assumed that the machine is continuously and uninterruptedly available. However, in the real world problems this is not the case (Pinedo [1]). The possible machine breakdown and interruption would be unavoidable in case of working continuously and also this may affect the quality of the jobs being processed by the machine. Thus, the periodic preventive maintenance process is usually planned and implemented to avoid the aforementioned problem. In this paper the scheduling problem is mathematically formulated subject to the amount of time the machine is available between the two consecutive periods, at the end of which the maintenance process is implemented and the maximum number of jobs which could be processed by the machine over the operating time. Jobs are done in two different ways when we have a limited time period in which the machine is available before the next maintenance process. In the first case, which is called preemptive jobs, it is assumed that operations of the in-process jobs could be continued after machine interruption. On the other hand, for nonpreemptive jobs, it is assumed that the incomplete jobs must be reprocessed after interruption. Also, for some manufacturing processes such as manufacturing of the electronic circuits, the number of jobs to process before changing the tools is a constraint. Considering Graham¡¯s three-field notation for symbolizing the scheduling problems, this case is specified with 1/nr-pm/ (Graham et al. [2]). The problem of machine availability has been widely considered in the
%U http://www.hindawi.com/journals/isrn.industrial.engineering/2013/936814/