Research On Simulation-based Assessment And Decision-making System Of Job-Shop Operating Plan

In recent years,manufacturing modeis turning from traditional massive production to small batch production in various customizational eras. Its features, such as diversity, process similarity, and differentsource combination,and uncertainty of demands, put forward higher requirements on preparation of more efficient job shop scheduling. Due to a variety of random factors, in terms of time, quantity, quality and cost,the physical production schedule and the scheduled operation plan will deviate during the actual production. As a modeling method, computer simulationcan be used in the model of the system on a real system or design a system to experiment in order to achieve the purpose of analysis, research and design systems. It can not only realize pre-execution or the law of motion and movement of the reproduction system, but also visualize operating characteristics of the manufacturing system or the effects of system implementation.In this paper, discrete job-shop problem is the object of study, which based ona practical single and small batch production conditions to monitor the integrated system GG-MES(Guangdong University of Technology-Manufacturing Execution System) and simulation of control theory. The author analyze GG-MES data model of scheduling system and3D simulation software Flexsim as a platform for the visualization of the job shop scheduling, proposing Simulation-based Assessment and Decision-making System of Job-shop Operating Plan including production scheduling subsystem and operating plan simulation subsystem of operating planThe main research contents are as follows:1.On the basis of analysis of job shop manufacturing system composition and characteristics, the author apply Flexsim simulation platform, which underlying data (shop layout, equipment information, job information,etc.), and scheduling optimization algorithm calculated the operating plan data; the author also apply the Flexsim entity library andglobal table to establish a3D dynamic discrete event simulation model, which focus on created automatically mechanism for data-driven simulation model, and an example is to verify the effectiveness of its mechanisms.2. Based on the first content, running the simulation model to simulate production process of real job shop. From utilization of equipment, averagejob waiting time and average through time to assess the execution effect of implementation of operating plan. In simulation modeling, thebehavior of operators, shop layout and the transit time of the job should be taken into account. Through simulation to acquire operators the actual behavior data and workshop production datain the process of production, submitting operation process of the simulation model and evaluate the simulation result of report to production management personnel, as a basis for the decision of fixingproduction scheduling.3. The prototype system is designed with Delphi7.0and SQL Server2005,including basic data management, operating plan formation, simulation model building and assessment report output of operating plan.4. Based on the content above, the usage and result are illustrated.