In this paper, Vendor Managed Inventory (VMI) model is combined with quality inspection policy according to defect fraction. This condition is found in a product with degree of component commonality of its raw materials. Calculation of optimal inventory policy will be carried out by considering the degree of commonality of the component and the presence of defective fractions in the ordering lot. We develop 5 (five) inventory policy models that represent the raw material quality inspection methods: (a) without inspection; (b) 100% inspection with replacement of defective raw materials; (c) 100% inspection without replacement; (d) acceptance sampling with replacement; and (e) acceptance sampling without replacement. The objective function of the five models is to minimize the combined total cost of VMI inventory and quality inspection. Based on the result, the optimum policy is the acceptance sampling without replacement. This policy results in 20.90% holding-cost saving, 57.51% shortage-cost saving, 53.08% quality inspection-cost saving, and 98.26% ordering-cost increasing compared to existing costs. This cost saving is obtained because the VMI supply chain system considers the component commonality, which is possible for a shorter lead time to occur which reduces inventory costs in the form of decreasing the cost of safety stock and the possibility of shortages of raw materials.