Abstract
A quality of a design result in the early stage of the product development is very important, because it has high impact on the basic and detailed design stage. However, especially in the early stage, the problem structure and kind is often not defined yet. This research focuses on the problem definition in the early design stage. Using product function and product structure, a system approach to declare the problem in product design is proposed in this paper. Two design example is examined by proto-type system; (1) an electric fan system and (2) large-scaled integrated circuit (system LSI). In conclusion, the possibility of deriving product constraints by grouping the dependencies defined inside the product model.
