Player A and Player B are atomic DEVS models. Behavior of Atomic DEVS Simply speaking, there are two cases that an atomic DEVS model can change its state : (1) when an external input comes into the system ; (2) when the elapsed time reaches the lifespan of which is defined by . (At the same time of (2), generates an output which is defined by .) . For formal behavior description of given an Atomic DEVS model, refer to the page Behavior of DEVS. Computer algorithms to implement the behavior of a given Atomic DEVS model are available at Simulation Algorithms for Atomic DEVS. Coupled DEVS The coupled DEVS defines which sub-components belong to it and how they are connected with each other. A coupled DEVS model is defined as an 8-tuple where is the set of input events; is the set of output events; is the name set of sub-components; is the set of sub-components where for each can be either an atomic DEVS model or a coupled DEVS model. is the set of external input couplings; is the set of internal couplings; is the external output coupling function; is the tie-breaking function which defines how to select the event from the set of simultaneous events; The coupled DEVS model for Ping-Pong Game The ping-pong game of Fig. 1 can be modeled as a coupled DEVS model where ;;; is described as above; ; ; and . Behavior of Coupled DEVS Simply speaking, like the behavior of the atomic DEVS class, a coupled DEVS model changes its components' states (1) when an external event comes into ; (2) when one of components where executes its internal state transition and generates its output . In both cases (1) and (2), a triggering event is transmitted to all influencees which are defined by coupling sets and . For formal definition of behavior of the coupled DEVS, you can refer to Behavior of Coupled DEVS. Computer algorithms to implement the behavior of a given coupled DEVS mode are available at Simulation Algorithms for Coupled DEVS. Analysis Methods Simulation for Discrete Event Systems The simulation algorithm of DEVS models considers two issues: time synchronization and message propagation. Time synchronization of DEVS is to control all models to have the identical current time. However, for an efficient execution, the algorithm makes the current time jump to the most urgent time when an event