T he Apollo XIII mission might have ended differently had it not been for the invaluable contribution of what was at that time the exotic discipline of Simulation. Since then, simulation has become an integral part of virtually every scientific and engineering endeavor.
Personal computers bring the art and science of simulation within common reach.
Tools of the trade are plentiful and the choices can often be confusing. A brief perspective on their evolution should help in determining their utility and usefulness for a particular purpose. S imulation can be defined as the examination of the behavior of a physical process or system by means of a digital computer. It is essentially a two stage process which consists of building a model and experimentation with that model. In modeling, the physical system is first represented by a mathematical model which is then converted into a form suitable for digital simulation.