Research On Production Scheduling Based On Simulation

The problem of scheduling in dynamic shops has been extensively studied for many years and it has received considerable attention from researchers. In practice, dispatching rules have often been applied for dynamic shops scheduling because of their ease of implementation and their low time complexity. Aiming at scheduling of production system consisting of multistage in which each stage has one or several machines. Scheduling methods, which is based on dispatching rules and routing rules, is presented; then Breakdown level, shop load level and the routing of jobs and shop floor configurations are considered in the comparative study to analyze their affect on scheduling rules.The main content of this dissertation is introduced in detail as follows:(1)Research and analysis of system, system simulation, advantage of system simulation, basic steps of implementing system simulation and its application in engineering is made. This thesis disserts the simulation software Arena, a detail analysis and comparison of today’s popular range of advantages and disadvantages of simulation software is made.(2) Aimed at scheduling of production system consisting of multistage in which each stage has one or several machines. Scheduling methods, which is based on dispatching rules and routing rules, is presented. Simulation model for scheduling of production system consisting of multistage is constructed to test dispatching rules and routing rules. Thirty combinatorial rules composed of ten dispatching rules and three routing rules are compared using four types of performance measures:average flow time, average tardiness, average work in process and average utilization, determining the combinatorial rules which can obtain the best performance index.(3) A comparative study on the performance of scheduling rules in two types of manufacturing systems:flow shops and job shops. Four dispatching rules are proposed. Mean, maximum, variance of flow time, proportion of tardy jobs, mean, maximum and variance of tardiness have been used to evaluate the performance of various scheduling rules. Breakdown level, shop load level and the routing of jobs and shop floor configurations are considered in the comparative study to analyze their affect on scheduling rules.