Research On The Model Of Vendor Selection And Purchasing Quantity Allocation In Jit Purchase

The purchase activity is one of the most important functional activities in enterprise. Material purchasing is an inevitable task to every enterprise in supply chain, no matter it is raw resources or parts purchasing of a manufactory, or commodity purchasing of distributor on the next level in the same supply chain. The purchase activity has already become the core of enterprise management, and it is also an important source to obtain profits. As we know, it plays an important role in product development, quality guarantee, supply chain management and the operation management of an enterprise. The concept of JIT has tremendously changed our attitude on purchase. JIT purchase requires vendors to supply the needed material to manufacture in the right time, at the right place, and with right quality. According to the foreign experience in applying JIT model, JIT purchase is the biggest obstacle. The success of JIT purchase application plays a critical part in executing JIT production effectively. JIT purchase can not only reduce storage level, but also increase inventory turnover rate, bring down lead time, improve quality of purchasing parts, and achieve satisfactory delivery goods. JIT purchase is the necessary request of JIT production. Therefore, the appropriate selection of vendors and reasonable allocation of purchasing quantity are of significant meaning in JIT purchase.This paper mainly discusses how to scientifically and rationally select vendors and allocate purchase volume among all selected vendors in JIT purchase. The study is started by the review of related literatures, and the major study contents are shown as follows:Part 1:The research background and meaning of this paper are introduced first. Then related literatures of vendor selection and purchasing quantity allocation problem in JIT purchase are reviewed. Finally, the research contents of this paper are generalized and combined into to a concrete research frame.Part 2:Basic concepts and related theories of purchase, JIT production and JIT purchase are discussed. The differentiations between JIT purchase and traditional purchase are emphasized.Part 3:Criterions, methods and process of vendor selection is presented, and on the basis of JIT purchase's characters, influence factors and selecting process of vendor selection in JIT purchase are put forwards.Part 4:A model used to solve vendor selection and purchasing quantity allocation problem in JIT purchase, is built up. According to the characters of JIT purchase, two decision models are constructed:the multi-product, single-period multi-objective mixed integer stochastic programming model, and the multi-product, multi-period multi-objective mixed integer stochastic programming model Finally, a solving method is given; that is, firstly, multi-objective mixed integer stochastic programming model is transformed into multi-objective mixed integer programming model,and then the multi-objective mixed-integer programming model is solved by minimum deviation value method.Part 5:Two numerical examples are respectively given, solving steps are introduced and then optimized results are analyzed. Therefore the model and solving methods are proved to be effective in solving vendor selection and its purchasing quantity allocation problem in JIT purchase.Part 6:A summary is concluded, which generalizes this paper's main contribution. The shortage of this paper and outlook of future research are also pointed out.