The need for supplier involvement in new product development process is going to be more intensive due to the increasing technology advances, product and technology complexity and the fast growth of international trade in today’s competitive markets. Therefore, firms have increased their collaboration with their suppliers in order to develop new products more effectively. However, this strategy influences the product development projects performance. Brown and Eisenhardt’s review on the previous studies in this research area reveals that though different factors and relations have been studied in supplier involvement in product development, the interactions among these factors are still incomprehensive [1]. Moreover, Takeishi has proposed an integrative framework for supplier involvement in product development in automobile industry [2]. In his framework, not only does he investigate automaker’s “internal capabilities” but also he includes “external coordination”, and their combined effect on component design quality as one of the main development performances. However, there are still some relationships among the OEM (Original Equipment Manufacturer) and its suppliers which have not been described clearly yet. This article concentrates on the three important factors which affect inter-firm product management process. These factors are (1) communication between OEM and its suppliers, (2) integrated problem solving, and (3) OEM’s degree of knowledge about the outsourced components. In addition, we investigate how these factors influence product development project performance criteria in terms of product quality, development time, and product innovation.