The Controlling And Warning Wip Research Based On Pull Type Production

With the development of economy and the progress of science and technology, consumers show the trend of diversification demand for products. In this competitive market environment, manufacturing enterprises want to improve the market competitiveness, the best way is to keep effective control of the production cost, shorten the production cycle. WIP inventory costs account for a large proportion in the manufacture cost. High inventory will not only increase the production cost of the enterprise, but also will extend the production cycle and delivery. However low inventory will also affect the continuity of production, causing production disruptions. In this context, this article will discuss how to effectively control WIP within reasonable for a long-term.According to the background and the purpose of the study, this article reviews domestic and abroad literature about WIP control, respectively expounds the pull and push type production mode, then analys the applicability of MRPII, JIT. On this basis, this paper put forward using TOC in pull type production mode to control WIP. And analys the method of calculating Kanban quantity and set the buffer analysis, put forward the method of calculating the buffer based on queuing thoery. In the calculation of the queuing theory parameters, qualified product rate and rework rate are considered to modify the cumulative demand. In addition, this paper also use the relative difference θ value of ideal and actual WIP to reflect the deviation degree between the actual WIP and the ideal WIP. And the θ value is divided into different zones according to the current level of WIP and WIP management level, and early warning index is established to reflect the level of WIP. According to the warning messages, we can adjust the WIP between the processes. Finally, this article apply the early warning indicators in the actual production and discusses the results of case studies with longitudinal comparative analysis.In this paper, the case analysis results show that based on the pull mode of production of early warning indicators of WIP control has a certain practical effect. To a certain extent, Warning index reflect the status of the WIP, we can adjust the WIP inventory, keep the WIP inventory in ideal value range. This not only reduces the production cost, shorten production cycle and delivery, but also improve the ability of the system to respond to the fluctuation.