ABSTRACT
Like the design of any type of system, the design of a distributed real-time system is a creative process with a wide spectrum of options. If a system is designed from scratch, there is a wide design space that is bound by constraints. Constraints reduce the number of design alternatives to be considered. Unfortunately, not all constraints are known at the beginning of the design process. In practice, computer control is a feature that is often added to a system that, up to now, has been run without the help of computers. An example is a production line that is modernized. The basic architecture of that plant is likely to be retained. Thus, the design of the real-time control is faced with additional constraints, which are the result of the design process of the original production line.
