Abstract: Based on the fact that appending and solving auxiliary functions are always depended on solving the aim function during conceptual design phase for complex function, the con-ceptual design cyclic mapping model which supports cyclic solving between function layer, effect layer, principle layer and structure layer is put forward. It consists of three mapping pat-tern and twelve mapping relations, such as decomposing map-ping, solving mapping and deriving mapping. Then the key techologies such as of interface expression and mapping and function reasoning are discussed. Finally a computer aided conceptual design automatic software system is developed and the conceptual design of coin-assorter is given as an example.

Key words: Complex function solving, Cyclic mapping, Function prototype, Interface mapping