Perspective on interactive software for computer aided modeling and design of control systems

The paper summarizes experiences of development and use of software for computer aided design of control systems. Different ways to arrange the interaction with users having wide ranges of experiences are discussed. This includes question and answer dialog with macro facilities as well as different types of menu-driven systems. A comprehensive set of packages for modeling, identification, analysis, simulation, and design are described. problems associated with structuring, portability, maintainability, and extensibility are discussed. Experiences from development and use of the packages in teaching and industrial environments are discussed.