چكيده به لاتين
Supply chain management is a set of strategies for integrating chain members that aims to reduce costs and increase customer service. One of the most important issues for supply chain stakeholders is the provision and timely supply of items needed by chain members. Therefore, different types of models are presented as a purchasing strategy in the supply chain. In a group purchasing system, the participation and cooperation of a group of buyers is done with the aim of reducing costs such as ordering, shipping and purchasing costs. In this purchasing system, all members of the chain, including suppliers, buyers and customers of the supply chain, will win. The present research is a flexible group purchasing model for a group of citrus customers, each of which demands a certain degree of quality according to their needs. In this research, customers are clustered in terms of willingness to cooperate, amount and type of demand and distance from citrus sorting centers. This means that the customers who are most willing to cooperate and are closer to a sorting center are grouped together and rent that sorting center and buy directly from the gardeners. Also, the proposed method determines the combination of cooperation between customers in order to minimize costs. Costs include the cost of purchasing, renting sorting centers, transporting citrus fruits from orchards to sorting centers, and from there to customers. In order to simultaneously optimize the two objective functions, the revised multi-choice goal programming approach has been used. In the continuation of the case study of citrus customers, which includes citrus exporters, various processing factories, fruit and vegetable fields and etc., has been done in Sari city, which combines the structure of customer cooperation in the group purchasing system with the aim of responding. as if to offer demand and achieve lower costs. In fact, citrus customers cooperate with each other in order to be able to buy directly from gardeners in such a way that the ratio of demand from each quality grade to the total amount of demand is equal to the production ratio of that quality grade in orchards. Also, in order to reduce the purchase cost, the total amount of the group order should have a higher discount. The results of the research show that the costs in the case of customers cooperating with each other are 17% less than the case where customers meet their demands through intermediaries.
