Defining Real-time: A Background For The Design Of Real-time Knowledge-based Systems

Abstract

Dynamic real-time applications feature non-deterministic aspects that naturally match with the exploitation of the knowledge-based system technology. On the other hand, the use of the knowledge-based system technology makes even harder most of the difficulties of dynamic real-time system design. Because of this tradeoff, the design of real-time knowledge-based systems is still an advanced research topic. A fundamental open problem is the lack of a settled definition of the concept of real-time, which definitely states the requirements a software system must necessarily fulfill in order to be regarded as a certified real-time system. This paper proposes an original definition of real-time system, partly inspired by state-of-the-art definitions and partly based on an innovative problem decomposition perspective. Such definition is more formal than those that can be found in the literature, while being powerful enough to capture most of the real-time systems of practical interest in engineering domains.