The rapid evolution of computer technology has brought about the proliferation of new dynamic systems, mostly “man-made” and highly complex. Examples abound: computer networks, sensor networks and cyber-physical systems, automated manufacturing systems, traffic control systems, integrated command-control-information systems, etc
Historically, scientists and engineers have concentrated on studying and harnessing natural phenomena which are well modeled by the laws of gravity, classical and nonclassical mechanics, electromagnetics, physical chemistry, etc. Based on this fact, a vast body of mathematical tools and techniques has been developed to model, analyze, and control the systems around us. It is fair to say that the study of ordinary and partial differential equations currently provides the main infrastructure for system analysis and control.
On the other hand, much of the technology we have invented and rely on (especially where digital computers are involved) is event-driven: communication networks, manufacturing systems, or the execution of a computer program are common examples. Not only must these systems act as “event coordinators”, but they are also expected to swiftly react to unpredictable events, rapidly adapt to changing conditions, and guarantee their users satisfactory – if not optimal – performance. In short, all activity in these systems is due to asynchronous occurrences of discrete events, some controlled (like hitting a keyboard key) and some not (like a spontaneous equipment failure). This feature lends itself to the term Discrete Event System (DES). When systems combine both time-driven and event-driven behavior, we then deal with Hybrid Systems.
For more information, please see
Introductory Overview of Hybrid Systems from a Discrete Event System prespective