As customers' demands for diversified small-quantity products have been increased, there have been great efforts for a firm to respond to customers' demands flexibly and minimize the cost of inventory at the same time. To achieve that goal, in SCM perspective, many firms have tried to control the inventory efficiently. We present an mathematical model to determine the near optimal (s, S) policy of the supply chain, composed of multi suppliers, a warehouse and multi retailers. (s, S) policy is to order the quantity up to target inventory level when inventory level falls below the reorder point. But it is difficult to analyze inventory level because it is varied with stochastic demand of customers. To reflect stochastic demand of customers in our model, we do the analyses in the following order. First, the analysis of inventory in retailers is done at the mathematical model that we present. Then, the analysis of demand pattern in a warehouse is performed as the inventory of a warehouse is much effected by retailers' order. After that, the analysis of inventory in a warehouse is followed. Finally, the integrated mathematical model is presented. It is not easy to get the solution of the mathematical model, because it includes many stochastic factors. Thus, we get the solutions after the stochastic demand is approximated, then they are verified by the simulations.

  이 논문의 공급업체의 불확실성하에서의 신문팔이 문제를 다루고 있다. 즉 공급업체의 공급량이 소매업체가 주문한 양을 충족하기 못하는 상황을 고려한 것이다. 여기서 우리는 기대 이익을 최대화하는 최적의 주문량을 구하였고, 기존의 연구와 달리 소매업체의 위험 성향을 고려하기 위해 하향 리스크에 대한 제약 조건을 추가하여, 위험 성향이 높을수록 더 많은 주문량을 사용한다는 결과를 사례 연구를 통해 확인할 수 있었다.