In an era of major technological strides in computer interaction, it is a disappointment industrial designers continue to report that current CAD packages are too rooted in engineering design to be effective in supporting their own creative practices. This paper examines the nature of their dissatisfaction and proposes solutions. A comprehensive observational study of industrial designers' existing CAD and physical modelling activities is reported, from which an evidence base for the specification of improved digital industrial design tools is derived. Theories on design modelling, sketching, human cognitive development and CAD evolution are used to underpin the major conclusion that a conceptual shift in digital design tools must take place if industrial design is to be properly supported. The shift is discussed and illustrated through the presentation of plausible new HCI systems classed as 'virtual workshops' and 'intelligent environments'.