Computer-integrated manufacturing is generally agreed to consist of many sub-systems. There is, however, much less agreement as to what these sub-systems are, and how they relate to each other. These difficulties are compounded by the marketing policies of equipment vendors. A recent study under the ESPRIT program attempted to clarify the situation for the benefit of European industry as a whole. This article discusses the study results pertaining to defining sub-systems, and administering computer aided design.