This model uses historical mining costs for seven years to project costs for the coming year. The model forecasts line items for the coming year in two very different ways. First, it uses @RISK's Distribution Fitting tool to fit the historical data. This is a reasonable approach, but it can be argued that seven data values are not a sufficient basis for fitting a distribution. The second approach uses a more general distribution, the Trigen distribution. The bottom line is that the choice of input distributions can definitely make a difference in the distributions of the outputs.