Research On Mixed-model Assembly Line Modeling Based On Petri Net And Reconstrction Optimization

Mixed-model assembly line is best choice of the manufacturing enterprises producingmultiple and small batch products to adapt to market changes. But in the actual productionprocess, there is flexible capacity shortage problem result from fluctuations of short-tremdemand. In response to these issues, this article is intended to seek a way to improve theflexible capacity of mixed-model assembly line.The main content of this paper and the results obtained are as follows:First, made a classification of the workstation. Then established models of differenttypes of workstations using object-oriented timed petri-nets. We combined petri netmethod and object-oriented modeling technology during the building process. Andconsidered the time factor in the form of a one-dimensional array for the first time. Whenthe models were finished, two aspects of the properties and performance of models wereanalyzed.Put forward three different degrees adjustment means: using parallel mechanisms,adding bottleneck equipments and incresing the number of artcles being processed, basedon the analysis of different types of workstations. According to different process constraintrelations in workstations, the available adjustment means were different.Combining the three adjustment means and considering workstations as basicproductivity adjustment units,stadied reconstruction optimization of mixed-modelassembly lines. Took full account of factors such as time,cost,reconstructed effects.Considered delivery time and cost as constraints to ensure the completion of the order andthe effective of the reconstruction. Used balancing effects and reconstruction costs asobjective function to select the reconstruction program. The measure of the balancingeffects took load balancing index and balance loss into consideration.Designed a reconstruction algorithm of the above problem and programmed withC++language. After more than once runs of the program, we can get the optimal solutionof the reconfiguration problem. The proposed approach in this paper can be directly usedas a scheme, and also can be used as the reference of other adjustment scheme, such as balancing between different assembly lines and outsourcing.