Researches On Cell Formation Based On The Reverse Auction And Production Scheduling In Virtual Enterprises

With the intensification of market competition and the rapid development of modern information technology, the enterprise who only relies on production resources of his own is difficult to grasp the rapid transformation of market opportunities. At the same time, more and more enterprises only focus on their own core competitiveness of products. Virtual Enterprises(Virtual Enterprise, VE)are organized by enterprises with different advantages of resource for reclaiming market jointly. At the same time, as the demand of the personalized market has increased significantly, multi-variety and small batch has become the normal production mode of each enterprise. Cellular Manufacturing System(Cellular Manufacturing System, CMS) can identify the similarity of parts and claaify similar parts into group. CMS expands the batch of production and improves the efficiency of production when increasing the flexibility of production. In view of this, the article carries out the cellular manufacturing in virtual enterprises in order to make virtual enterprise adapt to muti-varieties and small batch production. And the article has studied problems of cellular manufacturing construction and cellular coordinated scheduling optimization under the environment of virtual enterprises, which is conducive to the rapid response to market demand for virtual enterprises.Cellular construction under virtual enterprises is the selection of multi-process routes of manufacturing tasks and manufacturing resources in essence, and the completion of processing tasks through the coordination of different manufacturing resources in essence. According to the similarity of technological process, core enterprises categorize similar parts into groups and form part families. The article divids parts in part families into several processing modules, and the same or similar modules will be clustered to form intermediate tasks. All those tasks are outsourced as units. Each intermediate task can be completed by physical manufacturing cells of multiple enterprises independently. Based on the concept of Physical Manufacturing Cellular(Physical Manufacturing Unit, PMU) and Logical Manufacturing Unit(Logical Manufacturing Unit, LMU) and Logical Manufacturing Process(Logical Manufacturing Process, LMP), the mapping relationship between manufacturing resources and manufacturing tasks is described in this paper. In this paper, the auction mechanism is applied to the production organization and the multi-attribute reverse auction model based on the game theory has been built, which auction each intermediate task separately. The article takes intermediate tasks as subject matters, core enterprises as auctioneer, candidate enterprises as bidders. The bidding process is the reverse auction process which considers the price, the quality, delivery date and other attributes. This article designs the bidding strategy, the expected revenue, the expected revenue of auctioneers and the scoring function strategy. The article evaluates the tender of bidding enterprises PMU and determines the cooperative enterprises PMU from the perspective of core enterprise. The ordered set of PMU of each cooperative enterprise has formed the manufacturing cells in virtual enterprises. The article simulates the auction process with the example, and the simulation results show that the proposed model is feasible.Cellular scheduling in virtual enterprises is a collaborative scheduling problem, which is also a multi-product and remote manufacturing-oriented problem. On the basis of the completion of cellular construction, this article describes the scheduling problem of manufacturing cells in virtual enterprises, and builds the mathematical scheduling model of collaborative production. With the scheduling target of minimizing the makespan, the article solves the scheduling model with hybrid algorithm of Particle Swarm Optimization and Tabu Search, which considers the normality of many precedence activities in virtual enterprises. To ensure all tasks completed on time and disturbance factors appearing in the process of production solved effectively, the article identifies the critical chain and adds the buffer mechanism before the bottleneck resource of the critical chain on the basis of the generation of scheduling scheme, which protects the bottleneck resources and verifies the model with the example.The article simulates the volatility occuring in the production process using software WITNESS, and the simulation results show the feasibility and effectiveness of the proposed model.In order to verify the operation effect of manufacturing cell constructing and production collaborative scheduling models under virtual enterprises in actual enterprises, this paper analyzes the product status and problems of GSI shipyard, and applies the proposed ideas to the part carrier and machinery fitting jobs of ship outfitting in this shipyard. After the generation of scheduling scheme, the article identifies the critical chain and adds the buffer mechanism before the bottleneck resource of the critical chain to ensure the completion of tasks. By the comparison of actual production in enterprises adopting the proposed model before and after, the result shows the feasibility and effectiveness of the proposed theory and method.