Types of Simulation
There are several types of simulation. The major types are probabilistic simulation, time dependent and visual simulation. In a probabilistic simulation one or more of the independent variables is conceptualized as a probability distribution of values. Time dependent or discrete simulation refers to a situation where it is important to know exactly when an event occurs. For example, in waiting line or queuing problems, it is important to know the precise time of arrival so that we can determine if a customer will have to wait or not.
Visual simulation is the graphic display of computerized results. Software for visual simulation is one of the more successful new developments in computer-human interaction and problem solving. Animation and visual simulation helps explain results to managers. Eliot (1997) notes "if you are analyzing a call center, you might show graphic icons of phones on the computer display and indicate the phones being answered as calls come into the call center. You could use colors, such as green for call completed and red for call abandoned, and otherwise make the simulation visually attractive to help other personnel understand just what the simulation is trying to do. (p. 14)."
Several software products are available for the implementation of simulations. Simul8 (from Visual Thinking Inc.) is a PC-based simulation package that costs about $500. It has animation and it interfaces with Visual Basic. Extend (from Imagine That! Inc.) is a more expensive and more complex modeling package. @RISK from Palisades uses Monte Carlo simulation. For more information on Simulation visit the INFORMS College on Simulation Web page athttp://www.informs-cs.org/.