Vendor Managed Inventory is a well-known vendor-retailer coordination approach in supply chain management where the vendor manages inventory of the retailer and determines the order interval and order quantity for the retailer. To consider practical situation, the upper limit of inventory for the retailer is set. If the inventory level for the retailer exceeds the upper limit, then the penalty cost is charged to the retailer. Furthermore, maximum allowable inventory level is set for the vendor to prevent the vendor from keeping much inventory. Single-vendor multi-retailer supply chain model with upper limit of inventory for vendor and retailers is studied. All the retailers’ are assumed to have the common cycle time, and a vendor manages retailers’ inventory and replenishes products. The mathematical formulation is introduced to minimize the total cost including the penalty cost violating the upper limit of inventory for retailers with the constraint of maximum allowable inventory level. The solution procedure based on Karush-Kuhn-Tucker (KKT) conditions is derived. KKT conditions are often applied to find an optimal solution of nonlinear programming problem with constraints. An illustrative example is used to show the application of the proposed solution procedure. Furthermore, sensitivity analysis is done to find out the relationship between maximum allowable inventory level and other values such as order quantity, the number of shipment, vendor’s cost, retailer’s cost, and total cost. As maximum allowable inventory level decreases, the number of shipment decreases but total cost increases. Order quantity has the trend of decline and is affected by the number of shipment.

Vendor Managed Inventory is a well-known vendor-retailer coordination approach in supply chain management. If the inventory level for the retailer exceeds the upper limit, then the penalty cost is charged to the retailer. Furthermore, maximum allowable inventory level is set for the vendor to prevent the vendor from keeping much inventory. Single-vendor multi-retailer supply chain model with upper limit of inventory for vendor and retailers is studied. All the retailers’ are assumed to have the common cycle time, and a vendor manages retailers’ inventory and replenishes products. The mathematical formulation is introduced to minimize the total cost including the penalty cost violating the upper limit of inventory for retailers with the constraint of maximum allowable inventory level. The solution procedure based on Karush-Kuhn-Tucker(KKT) conditions is derived.

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.

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.

Recently, Vendor Managed Inventory(VMI) has been commonly recognized as one of the supply chain application that delivers clear value to the sectors of electic & electronic components. VMI is a process in which a supplier generates orders for its distributor based on demand information sent by the distributor. VMI is providing the benefits of smoother demand, lower inventories(work in process, safety stock) and reduced costs. This study focused on improvement of safety level inventory efficiency by VMI. The results indicated that VMI allowed the company to serve its customers more surely and efficiently.