Model And Simulation Based On Petri Nets Job_shop Dynamic Scheduling Problem

In recent years, with the market competition aggravating and the customer's various needs increasing, the manufacturing mode of the modern enterprise is developing towards the direction that is'breed diversity, small batches, short delivery date and low inventory'. Job shop scheduling which solves the problems of scheduling and resources distribution becomes an important part of factory management and product manufacturing, and the bottleneck which is the resistance of enterprises grows. Nowadays, it is one of these problems needed to be settled promptly.In this paper, based on the analysis of the job shop dynamic scheduling problem, through using the Colored Petri Net with Inhibitor Arcs (CPNIA), the model of the job shop dynamic scheduling is presented, and is simulated and analyzed using CPN Tools. This paper mainly focuses on the following areas: (1) Descries the characteristics and the classification of the job shop dynamic scheduling, points out the existence questions; (2) Introduces the basic theory on Petri net and a simulation tool, CPN Tools, which is based on Colored Petri Net (CPN). It is introduced how to model and analyze using CPN Tools; (3) Through integrating CPN and petri net with inhibitor arcs, a petri net named CPNIA (Colored Petri Net with Inhibitor Arcs)is presented and used to model the Job Shop dynamic scheduling, in which three cases are fully considered, such as device maintenance, device breakdown and workpiece priority; The model of a concrete example is simulated and analyzed by CPN Tools without time; (4) The model of a concrete example is simulated and analyzed by CPN Tools with time.The simulation result shows that the model has strong dynamic responding capability to device maintenance, device breakdown and workpiece priority. At the same time, it shows that the model has effectiveness and correctness.