It is apparent that the development or implementation of a collaborative product development management (CPDM) system in an enterprise should be based on the right understanding of core domain objects, their main attributes, and their relationships to other objects in the product development domain. For this purpose, an object-oriented conceptual model of a CPDM system based on a top-down approach is presented in this paper. For building the conceptual model systematically, this paper proposes the 4P2C modeling views, which are multifaceted views of engineering information that provides an integrated and consistent perspective on engineering information. The 4P2C stands for product, process, project, participant, cost, and collaboration. Based on the 4P2C modeling views, six submodels are constructed that eventually constitute a complete conceptual CPDM model. In each sub-model, the decomposition of core domain objects, their main attributes, and their relationships to other objects are represented in detail. A prototype application program along with an illustrative cost calculation example is also presented to demonstrate that the proposed CPDM model will enable enterprises to maintain consistency in product data efficiently throughout the product life cycle.