The data to drive the simulation ca

The data to drive the simulation can be generated in several ways. The most common method uses a random-number generator that is programmed to generate processes,
CPU burst times, arrivals, departures, and so on, according to probability distributions.
The distributions can be defined mathematically (uniform, exponential, Poisson) or empirically.
If a distribution is to be defined empirically, measurements of the actual system under study are taken.
The results define the distribution of events in the real system; this distribution can then be used to drive the simulation.