Simulation is a powerful tool for the analysis of new sysIn concept, a model’s state is a (long) vector, that is, a list of values that are sufficient to define the state of the system at any point in time. In practice, a model’s state is

tem designs, retrofits to existing systems and proposed changes to operating rules. Conducting a valid simulation is both an art and a science. An event is an instantaneous occurrence that changes the system's state.