1. Continuous-Variable Dynamic Systems(CVDS) must satify:
(1)They are continous-state systems.
(2)The state transition mechanism is time-driven.
2.Discrete Event Dynamic Systems(DEDS) must satify:
(1)The state space is a discrete set.
(2) The state transition mechanism is event-driven.
3.definirion.
A Discrete Event System(DES)is a discrete-state,event-driven system,that is, its state evolution depends entirely on the occurence of asynchronous discrete events over time.
4.We should not confuse discrete event systems with discrete-time systems.
The class of discrete-time systems contains both CVDS and DES.A DES may be modeled in continuous or in discrete time.
5. Three levels of abstraction at which DES are modeled and studied:
untimed(or logical), timed,and stochastic.
6. Two discrete event modeling formalisms will be presented and studied:automata and Petri nets.
next 1.3.4 Example of Discrete Event Systems ----P57