The startling increase in performance, quality and sophistication in today's engineering products requires all agents participating in the process of product development to exchange information with one another through a product model, which enables the communication of the design between participants in the process of product development. The objective of this paper is to present a product model, which includes the assembly states to support various activities, involved in the assembly process. Because of its more comprehensive approach, this model both bridges the gap that exists in current Computer-Aided Design (CAD) and Manufacturing (CAM) systems and proves valuable in the design of all-inclusive systems combining various stages in the development of a product.