ABSTRACT
Real-time systems are defined as those systems in which the correctness of the system depends not only on the logical result of computation, but also on the time in which the results are produced [Stankovic 1988]. Real-time systems span a broad spectrum of complexity from very simple microcontrollers in embedded systems (such as a microprocessor controlling an automobile engine) to highly sophisticated, complex, and distributed systems (such as air traffic control for the continental U.S.). Other examples of real-time systems include command and control systems, process control systems, flight control systems, the Space Shuttle avionics system, flexible manufacturing applications, the space station, space-based defense systems, intensive care monitoring, collections of humans/robots coordinating to achieve common objectives (usually in hazardous environments such as undersea exploration or chemical plants), intelligent highway systems, mobile and wireless computing, and multimedia and high-speed communication systems. We are also beginning to see some of these real-time systems adding expert systems [Wright et al. 1986] and other artificial intelligence (AI) technology creating additional requirements and complexities. From this extensive list of applications we can see that real-time and embedded systems technology is a key enabling technology for the future in an ever growing domain of important applications.
