If the formulation above and some phenomena is same.
Then this formulation is used for prediction.
For example,
"If X = 3 and Y = 1 then Z = 3"
Method for prediction and experiment with computers. There are three interesting points.
Design of Experiments is useful because efficiency is also needed in simulation.
Random sampling is the ideal study in Statistics.
In real study, random sampling is very difficult. But in simulation, we can use random sampling easily. Dispersion Model is one of this approach.