Product support, which is also referred to after sale service to the product is important for customer because it increases the availability of the product and it assures the expected function of the product in its operational phase. It gets affected by many factors such as - reliability and maintainability characteristics and geographical location of the product. By highlighting the reliability issues and geographical distribution of product in design and manufacturing phases, the product life cycle cost (LCC) can be optimized. One of the important steps in product design is the decision making for design out maintenance (DOM) and/or designs for maintenance (DFM). The DOM alternative leads to produce high reliable, and vice versa, whereas the DFM assure the similar performance with lower reliability. However, the need for product support and spare parts must be considered in both alternatives. The forecasting of required product support and spare parts based on reliability-maintainability characteristics is one approach for the product LCC optimization. Consequently, spare parts inventory management based on geographical distribution and reliability characteristics of the product can be also used as an alternative. This article describes a method to forecast the spare part requirements based on reliability estimation of the existing product under the influence of the product-operating environment. Subsequently the management of the spare parts inventory will be discussed based on the geographical location and required performance of the product.