There are basically two modes for statistics, Global Minimum and Overall Slope. Tutorial 8 discusses the Global Minimum option, while Tutorial 11 goes over the Overall Slope option.
The Global Minimum option finds the global minimum for the mean parameters and then runs statistics on that surface.
In the case of Overall Slope, for each monte carlo simulation, an instance of the material properties based on the statistical distribution is sampled, and the program then finds the global minimum. This option is much more time intensive, since for 1000 monte carlo simulations the program computes 1000 global minimums.
The Global Minimum option is good if the location of the global minimum does not change as a function of the input random variables. The Overall Slope option is better if the location of the global minimum surface does change.