The inventory routing problem (IRP) is an important area of Supply Chain Management. The objective function of IRP is the sum of transportation cost and inventory cost. We propose an Artificial Immune System(AIS) to solve the IRP. AIS is one of natural computing algorithm. An hyper mutation and an vaccine operator are introduced in our research. Computation results show that the hyper mutation is useful to improve the solution quality and the vaccine is useful to reduce the calculation time.

  Operational strategy for inventory control in the distribution system has been given attention. If an individual enterprise implements the strategy, it is not easy to gain scale merits because of limited quantity or burden of inventory. In this study, w

  In this paper we suggest the methods that compute the total inventory cost based on EOQ and the total inventory cost based on OMMIP. The total inventory cost consists of purchasing cost, ordering cost, inventory holding cost, stockout cost and so on. Th

In this paper, we examine the effect of demand variability in multi-item inventory systems where supply lead-times are endogenously generated by a production system with finite capacity. In contrast to systems with exogenous lead times, we show that variability in lead-time demand actually decreases with demand variability. We also show that higher demand variability leads to a smaller fraction of total stock being devoted to safety stock. More significantly, we show that a sufficiently large increase in demand variability can lead to the elimination of safety stocks altogether. These results suggest that strategies used to reduce lead-time demand variability would be less valuable when demand variability is high.

본 연구는 공급자, 중간분배자 그리고 고객으로 구성된 2 단계 공급사슬에서 시간에 따라 일정률로 퇴화하는 퇴화성 제품을 취급하는 중간분배자의 경제적 재고모형을 분석하였다. 문제 분석을 위하여 공급자는 고객으로부터의 수요를 증대시키기 위한 수단으로 일정한 묶음 단위별로 일정한 양의 덤을 제공한다는 가정 하에 재고모형을 설계하였고, 모형 분석을 통하여 이익을 최대화하는 경제적 주문량 결정 방법을 제시하였다. 또한 예제를 통하여 제시된 해법을 적용하고, 그

  기업의 수요에서 자기상관을 인식하지 못하게 되면, 이 기업은 수요가 서로 독립이면서 동일한 분포를 따른다는 가정 하에 개발된 전통적인 재고주문방법을 시행하게 된다. 따라서 이 경우에 안전재고량, 재고부족 확률, 재고부족량 등과 같은 성과지표의 관점에서 전통적인 재고주문방법이 정확한 재고주무방법에 비하여 얼마만큼 비효율적인가를 알아보는 것은 기업경영의 측면에서 의미 있는 일이다. 이 논문에서는 정기주문시스템 하에서의 두 가지 재고 관리방법을 비교하기

  In this paper, we consider an inventory system where a single supplier purchases and processes raw materials into finished goods in order to deliver finished goods to a single buyer for effective implementation of Just-In-Time Purchasing. An integrated

  It has been a major issue to repair the broken system quickly for improvement of productivity and utilization. Generally, high utilization of system requires the high amount of spare parts in inventory and inventory cost. Therefore, it is necessary to d

  A company establishes a sale strategy through the inventory to set the purchasing requisite of the customer in a global company environment. And a sale company can become the reason of a sale opportunity loss because of a customer satisfaction rate if i

As competition in manufacturing enterprise is contested, the scope of safely production planning, manufacturing enterprise should ensure, has been reduced. The more upstream of SCM, the more reduction of scope of production planning. As a result, order fluctuation is more sharply contested. Through improving the logistics network, it is best way that the end user's demand information is conveyed to upstream of SCM, but it is difficult in fact. In this paper, it mention the way of robustic adjustment, in the suppliers' point of view, the end user's demand information is dammed up, as they postpone responding the customer's order as a possible. And it will show the result of appling the way, as a case study.

  The National Wealth Survey Method has been used to estimate capital stocks in Korea by the Korea National Statistical Office in every 10 years. However, this method requires huge amount of time and money. Since the Benchmark Year Method also has similar

A wastewater treatment plant consists of unit processes designed to achieve specific waste reduction goals. However, offensive odors associated with the treatment processes are a constant source of public complaints. The purpose of this study was to statistically determine the process parameters that influence the formation of volatile sulfur conpounds (VSCs) in the secondary treatment system. A statistical model was developed to relate the process parameters to the formation of VSCs in this system. The model established that F{M ratio, sludge blanket depth and SSV60 were the dominant process parameters that would influence the formation of VSCs in the secondary sedimentation basin. This model provides a useful tool for plant engineers to predict and control the VSCs formation in an secondary activated sludge system.

The main focus of this study is to investigate the performance of a clark-scarf type multi-echelon serial supply chain operating with a base-stock policy and to optimize the inventory levels in the supply chains so as to minimize the systemwide total inventory cost, comprising holding and backorder costs as all the nodes in the supply chain. The source of supply of raw materials to the most upstream node, namely supplier, is assumed to have an infinite raw material availability. Retailer faces random customer demand, which is assumed to be stationary and normally distributed. If the demand exceeds on-hand inventory, the excess demand is backlogged. Using the echelon stock and demand quantile concepts and an efficient simulation technique, we derive near optimal inventory policy. Additionally we discuss the derived results through the extensive experiments for different supply chain settings.

A number of stores can save costs by forming a centralized inventory system. The number and location of centralized warehouses can be determined in minimizing total costs and then these cost reductions should be allocated fairly to each store. If no group of stores feel that they are paying to subsidize to the complementary set of stores, then that cost allocation is in core. That is, all stores become better off by forming a group. This study shows that there does not exist the core in some examples. Hence, we suggest a framework for the cost allocation both of the case in which the core exists and the core does not exist.

본 논문은 제품공급자, 중간분배자 그리고 고객으로 구성된 2 단계 공급사슬에서 공급자가 수요 증대를 목적으로 중간분배자에게 일정기간 동안 제품대금에 대한 지불연기를 허용하는 상황을 고려하여 중간분배자의 신뢰성있는 판매가격 및 재고보충정책을 결정하는 문제를 다루었다. 문제 분석을 위하여 고려하는 제품은 시간에 따라 일정률로 퇴화한다는 가정과 함께 수송량에 따라 할인되는 수송비를 고려하여 모형을 수립하였고, 중간분배자의 수익 증대를 위한 경제적 판매가격 및

VMI(Vendor Managed Inventory)가 사회적인 관심사로 부각되고, 전 부분으로 확산 되고 있음에도 불구하고 VMI의 도입적용에 관한 연구 및 문헌자료는 찾아보기 힘들 정도로 부족한 실정이다. VMI에 관한 연구의 대부분이 재고기법에 관한 응용연구에 편중되고, 공급체인상의 하부기능으로 일부 언급되었을 뿐, 공급체인상의 프로세스를 중심으로 VMI의 실증연구가 이루어진 자료는 전무한 실정이다. 이러한 상황에서 VMI의 도입 구축 프로젝트추진을 계기로 VMI의 적용에 따른 물류 프로세스 개선에 관한 연구를 하였다.