In this work, a mechanical design is represented using design features and manufacturing features. A design function based design feature representation is introduced. This representation allows design candidates to be generated by a pattern match search in the design feature library, according to given design requirements. A fuzzy c-means clustering algorithm has been used for organizing design features in a large feature library. A fast feature searching scheme has been developed for quick feasible design identification. The manufacturing feature representation is based upon the geometric primitives produced by various manufacturing operations. The representation can provide a useful design database for manufacturing tasks. It also provides a list of necessary manufacturing processes and their associated costs for manufacturing each design candidate. The method supports the generation of multiple design solutions and joint evaluation of design performance and manufacturing costs, thus providing the basis of concurrent engineering design. The design feature and manufacturing feature coding methods are tested using a prototype feature-based, integrated concurrent engineering design system.