Types of Non-Controlled Variables

a) Parameters:

These are input variables that for a given simulation have a constant value. They are factors which help specify the relationship between other variables e.g. in pdn simulation the time taken for routine maintenance, the cost of stock-out, etc.

b) Status Variables:
Status variables may be used to specify the days and seasons to be used in a simulation e.g. demand may be affected by the day of the week

c) Output Variables:
These are the outcomes of the simulation. They occur from the computations and tests executed in the model. The output variables should be carefully selected to reflect the factors that are critical to the real system being simulated and they should associate to the objectives of the real system.  E.g. the output variables for an inventory simulation would include: Cost of holding stock, number of stock-outs, number of unsatisfied orders, number of replenishment orders, and cost of the re-ordering etc.