The Effect of the Processing Time's Variance to the Performance of Sequencing Rule

Abstract

SPT was the most studied rule in sequencing. Most of the research concluded that SPT was the best rule but other research concluded that SPT did not achieve the best performance. Studies shown that performance varies due to a great different environments because there were so many factors affected the performance. One of the factors that lead to differences in the conclusions was varying of processing time. The objective of the paper was to evaluate the effect of processing time's variance to the performance of sequencing rules. Only processing time variance was being investigated while number of machine was treated as nuisance factor. To achieve this objective, an experiment was designed and the experiment result was analyzed using anova. Performance measure used in the experiment was lateness. Only five sequencing rules were used. The rules were First In First Out (FIFO), EDD, SPT and Slack Time. The experiment found that for a small number of job, the effect of processing time's variance was not significant to the performance of sequencing rule. For large number of jobs, processing time's variance had a significant effect on the performance of sequencing rule. For further research, more sequencing rule to be consider while some assumptions is relaxed.