Presents a formal model for specification of logical requirements of computer-based information systems that incorporates structural and dynamic aspects based on two separate models: the Logical Information Processing Structure and the Logical Information Processing Network. The model's role in systems development is discussed. (MBR)

Discusses what designers do, information they need, and how they might be aided, as background information for developing useful computer-aided decision systems to enhance designers' productivity. It is concluded that effectiveness of computer-assisted design systems depends on the value of the information and the flexibility of the support they…