Abstract This paper introduces formal definitions to system requirements as the basis of design automation. Semi‐formal requirements for real‐time systems are expressed in the form of system verification diagrams, and the graph model of behaviour represents the design, capturing three aspects of system behaviour—control, data and interpretation. The design model is consideredoperationalas an underlying token machine governs its actual behaviour. To achieve automatic design synthesis, the semantics of each construct in the requirement model have to be formally defined. These definitions constitute the core of a knowledge base in an automatic design synthesis tool.

In this research in design automation, two views are employed as the requirements of a system-namely, the functional requirements and the operations concept. A requirement analyst uses data flow diagrams and system verification diagrams (SVDs) to represent the functional requirements and the operations concept, respectively. System Architect's Apprentice (SARA) is an environment-supported method for designing hardware and software systems. A knowledge-based system, called the design assistant, was built to help the system designer to transform requirements stated in one particular collection of design languages. The SVD requirement specification features and the SARA design models are reviewed. The knowledge-based tool for synthesizing a particular domain of SARA design from the requirements is described, and an example is given to illustrate this synthesis process. This example shows the rules used and how they are applied. An evaluation of the approach is given.>