Discrete-Event Systems
Christos G. Cassandras · Birkhäuser Boston eBooks · 2005
The term “discrete-event system (DES)” was introduced in the early 1980s to identify an increasingly important class of dynamic systems in terms of their most critical feature: the fact that their behavior is governed by discrete events occurring asynchronously over time and solely responsible for generating state transitions. In between event occurrences, the state of such systems is unaffected. Examples of such behavior abound in technological environments such as computer and communication networks, automated manufacturing systems, air traffic control systems, Command, Control, Communication, Computers, and Intelligence (C 4 I) systems, advanced monitoring and control systems in automobiles or large buildings, intelligent transportation systems, distributed software systems, and so forth. The operation of such environments is largely regulated by human-made rules for initiating or terminating activities and scheduling the use of resources through controlled events, such as hitting a keyboard key, turning a piece of equipment “on,” or sending a message packet. In addition, there are numerous uncontrolled randomly occurring events, such as a spontaneous equipment failure or a packet loss, which may or may not be observable through sensors. We should point out that the acronym DEDS, for “discrete-event dynamic system,” is also commonly used to emphasize that it is the dynamics of such systems that render them particularly interesting [1],[2].