Research Of Production Scheduling System In MES

MES (Manufacturing Execution System) lies between plan managerment level and production control level, works as an information bridge in an enterprise's informationization, its main function is production scheduling, so this dissertation studies MES emphases in its production scheduling system. This dissertation fistly introduces appearance, definition, development process, functions and status of MES, also analyses methods and existent problems of MES production scheduling; as follow, in the background of CY_MES (a enterprise's Manufacturing Execution System), introduces main function and buildup of its support platform– SIMATIC IT, and whole structure of CY_MES; afterwards, for special production instance of the enterprise, designs production scheduling system software structure, function structure, data structure of order and entry and realization of silk production and packing production scheduling based on SIMATIC IT; finally, after contrast of many modeling methods and careful research of silk production flow of the enterprise, selects Petri net to model the silk production scheduling, for the sake of avoiding many error chromosomes, improves on the basic genetic algorithm, uses sigle unit genetic algorithm to optimize the Petri net model, lists the contrast of scheduling results. Runing instance and simulation programme indicates that, combination of petri net and genetic algorithm is proper to solve silk production scheduling, and can be used for reference in other similar production scheduling.