Research And Application Of Dynamical Scheduling Subsystem Of Manufacturing Based On MES

Manufacturing Execution System ( MES ) is the execution system connecting plan management in enterprise level and industry control in understratum.MES analyzes management information of plans from ERP(Enterprise Resource Plan), and transfers operating instructions to Production Control Layer(PCL).On the other hand,MES collects spot data of manufacturing,analyzes,computers and disposes the data,then triggers new events to associates control system and information system expediently and reliably.It is the execution of the plan that MES emphasizes,So the prior aim of the system is to build executable instructions of production scheduling.Combining the manufacture fact in QingDao tobacco factory, the thesis designed a subsystem of dynamic scheduling of manufacturing based on plenty of analysis of demands and architecture defined in S95 international normal.This system can receive production plans from ERP,analyze them into operations that can be done directly by workshop,and release them to Production Control System.It resolved applied difficult problems of production scheduling effectively,improved plane of production management and enhanced production benefit.This thesis analyzes the manufacture characteristics of discrete,sequential and hybrid process firstly,then analyzes the manufacture characteristics of tobacco industry as hybrid process and analyzes requirements of dynamical scheduling subsystem by data flow graphic,and elicits business functions and assistant business functions of dynamical scheduling subsystem.From the layer that MES lies in the information systems of enterprise,this thesis provided software structure of dynamical scheduling subsystem based on Simens SIMATIC IT.This thesis used the graphics mode to design function module such as secondary scheduling,primary scheduling,filter scheduling,stem scheduling and assistant modules from the top to the bottom.On the other hand,this thesis adopted thought of three-layer architecture to design the logical function module of the system,as splits data layer,business layer and user layer each other from logic.This reduced coupling of system modules and made the system to be better extensible and better maintainable.The thesis studied the strategies of dynamical scheduling based upon scrolling windows.The algorithm of secondary dynamical scheduling was based on this strategy.The author designed algorithm flow for secondary scheduling.This thesis also studied algorithms such as capacities balance of equipments,simultaneous halt of several equipments of packers by dichotomy approaching infinitely.Besides,This thesis studied algorithms such as lot plans of primary and primary scheduling,too.The research on this project provided a practical and efficient solution for dynamic scheduling in tobacco enterprises.In the process of dynamic scheduling,the system can find some problems about production emerged in the production taches such as material shortage,equipments hitches etc.,response to them fleetly and resolve them in time.At present,the software has been put into run,and better meets the demands of practical scheduling of workshop.