Functional reasoning in design

A product design process begins with functional or conceptual design, followed by basic design and detailed design. Among these, functional design plays the central role in ensuring design quality and product innovativeness. Because function is the most crucial concept in designing better and more innovative products, functional reasoning technology is indispensable to the development of future advanced CAD technology. This survey shows how functional reasoning has successfully established the representation of function on computers and outlines directions for further research.