Figure 1: The basic design (Roozenburg and Eekels, 1995) Point of departure in product design is the function of the new product, ie. the intended behaviour in the widest sense of the word. We do not only include the technical function, but also the psychological, social, economic and cultural functions that a product should fulfil. The function need not be laid down in all detail this is even broad statements on the function must have been made, otherwise the designer does not know what has to be designed.