Direct Engineering (DE) is the creation of a product development cycle into a single, unified process. The design process in most industries is an evolutionary one (i.e., incremental changes to some existing design). DE is a manufacturing process that seeks to improve the design processes by providing complete archival documentation of existing designs. It uses three-dimensional geometric models with integrated manufacturing information throughout the design process. DE reduces the design cycle, and the variety and number of engineering changes. This process decreases the design cycle time, increases productivity, and provides a higher quality product. The required technologies and methodologies that will support the development of the DE environment are: (1) product representation using feature-based modeling; (2) knowledge-based applications that will support the entire product development cycle; (3) an engineering environment implemented around distributed computing and object-oriented systems; (4) direct manufacturing techniques using rapid prototyping. Direct Engineering: Toward Intelligent Manufacturing addresses the following recent topics related to the development, implementation, and integration of the DE environment: (1) the current scope of the research in intelligent manufacturing; (2) the results of the technologies and tools developed for integrated product and process designs, and (3) examination of the methodologies and algorithms used for the implementation of direct engineering.