Research On The Optimal Number Of Suppliers And Order Allocation Problem Under Uncertainty Environment

There are many uncertainties in the supply chain management. These uncertaintiesmake the supply chain management and vendor selection becoming more difficulties,especially the uncertainties of the demand of customers and the capacity of suppliers. Thesuppliers are the source of the supply chain; and they are critical to the survival anddevelopment of the enterprises. So, studying in the supplier selection and order allocationproblems not only has great importance in theory value, but also has high practicalsignificance to the enterprise.Recognizing the importance of the vendor selection decision, an extensive literatureexists to address this kind of decision. These existing decision making models areessentially trying to answer the following basic questions: how many suppliers areappropriate, which suppliers to choose, and what is the optimal ordering policy. The maindisadvantage of these deterministic models is their incapability of handing randomnessembedded in the real system.Firstly,under the premise of the supply disruption risk caused by various kinds ofuncertainties and transaction cost,the paper puts forward an optimization model toeffectively decide the optimal number of suppliers The supply disruption risk events arecategorized into "common risk event" and "single risk event". Considering the "trade-off"between the supplier selection transaction cost and financial lost caused by the supplydisruption, a quantitative method is used to analyze the problem of the optimal number ofsuppliers. And a model of calculating the optimal number of suppliers is established. Andanalyze each parameter’s influence on the optimal number of suppliers.Secondly, on the assumption that the user’s demand and the suppliers’ capacity arerandom, with the consideration of quantity discount, a multi-objective vendor selectionand order allocation optimization model is developed based on purchasing cost,transaction cost, transportation cost, the number of late deliveries and quality. Then themulti-objective programming is transformed into single objective programming by usinglinear weighting method. The model not only could determine the optimal suppliers, but also could determine the optimal order allocation amount of each selected supplier.In the end, the paper takes YX company as an example, and makes an empiricalanalysis on the models put forward in the article.