VMI is an operation model under the supply chain environment. Compared with the traditional method of replenishing upon client’s order, VMI turns the multi-level supply chain issues into a single-level inventory management issue. By taking the actual or predicted consumption demand and inventory as a solution of predicting market demand and replenishing inventory, the supplier and the client enter into a common agreement, under which the supplier manages the inventory and keeps supervising the implementation of the agreement so as to realize a continuous improvement of inventory management aiming at a minimized cost beneficial to both the client and the supplier. VMI is a major inventory management model in Real Logistics business.