عنوان مقاله [English]
In today's world, the ultimate goal of many businesses is to reduce costs. Also, finding efficient ways to achieve the best results is important to make correct managerial decision. In supply chain system, minimizing costs due to the nature of the deterioration of certain products is concerned and also, finding ways to obtain optimum conditions is essential. The two-level supply chain system with suppliers, distributors and retailers was investigated in this research. Decision variables of this problem due to minimizing costs, are determining of the appropriate initial weight for packaging of deteriorating products and determining of appropriate inventory levels in multi-level supply chain. The Intended product is gradual deteriorating package that is produced and sent by the supplier with a value greater than unit. Shortages for the backlog and also lost sales have been considered. This study is based on a case study of detergent company data. In this study, through simulations to study the behavior of decision variables are discussed. Customers refer to retailers to provide their needs. Customer entrance rate is defined probability Poisson. Based on the considered (S-1,S) ordering policy caries out two operations as soon as entering a retail client. The first one is to order product to distributor and the other is to provide customer needs. Neighbor search method and ARENA software sub-program is used to find optimal points. Then using flexibility of ARENA software, study of cases that are very complex through
mathematical modeling and increasing the amount of system uncertainty have been possible. The effect of the implementation period and the number of occurrences that led to the introduction of the points by choosing them can be trusted to extract the results. Using the duration and number of occurrences obtained optimum levels for retailers and distributors, and the surplus was calculated by neighbor search method. At last, the minimum cost for unit product and the extra amount required for a product are calculated by taking into account certain assumptions.