An interactive system is described which allows for the graphic construction, simulation, and simultaneous animation of an arbitrary network of guesses. A method is proposed and implemented for representing the events of a discrete simulation by a continuous animation on a graphics terminal. Techniques are presented for the display of parallel animation "sequences", and a non-trivial mapping of simulation time into animation time is described which preserves the relation order and time relationships between events. The program implemented combines this animation facility with other simulation monitoring and control features. An interactive dialogue which makes use of the lightpen and a menu of commands is implemented for the construction and modification of the queuing network. Certain relevent aspects of man-machine interaction are discussed. The usefulness of this type of approach is discussed with respect to computer-aided design applications, educational tools, and research tools.