Increasing demands for lower cost of goods, due to international competition, has developed a new area of rationalization for increased productivity which can be achieved by applying new radical methods of production principles. Design for Assembly (DFA) is one of such methods that should be considered in the early design stage in order to cope with the increasing demands of lower cost, improved working environment, and higher wages. When Axiomatic Design (AD) is implemented with DFA in an intelligent way, a new area of design concepts would be realized. This study examines some elements of intelligent design systems to assess manufacturability of a product through the development of a knowledge based expert system for assembly (KBESA). The knowledge base has been acquired from DFA along with AD concepts with emphasis on the conceptual design stage where the structure of the product as a whole is considered. These concepts have been implemented in a case study illustrating its applicability.