Lejmi, T.Sabuncuoğlu, İ.2016-02-082016-02-0820020020-7543http://hdl.handle.net/11693/24730In real manufacturing environments, variations in production factors (i.e. pro- cessing time, demand, due-dates) are inevitable facts. All these dynamic changes, together with random disturbances (e.g. machine breakdowns) can seriously a ect the system performance. In this paper we focus on load, processing time and due date variation and analyse their impacts on a scheduling system. Speci®cally, we investigate the impact of variation on dispatching policies in a job shop environ- ment via simulation. The statistical analysis of the results leads to two major conclusions: ®rst, the relative performance of rules is not threatened much by PV (processing time variation), LV (load variation) or DDV (due date variation) Ð a result that can be a consolation for practitioners in the ®eld. Secondly, the performance of the rules deteriorates, in particular at high levels of PV, LV and DDV Ð a result that can provide new insights into the problem and produces useful information for researchers in their continuous e ort to develop better dispatching rules.EnglishComputer simulationEstimationManufactureOperations researchOptimizationPerformanceStatistical methodsDue date variationJob dispatching environmentLoad variationProcessing time variationSchedulingArticle10.1080/00207540110098481