Parametric Studies allow you to change boundary condition values and batch run multiple studies. You can select the values that you're interested in or you can select a step size to very the boundary condition with.
The latest 2017 version of Solidworks does this in a more efficient way, where it uses the Taguchi method to run the simulations where multiple boundary conditions are altered.
To add one more note to what Alex mentioned, it seems that running a simulation with new boundary condition should be through New Calculation option.But that is not my concern now...
Here is an interesting outcome of a simple test:
With Take the previous results option: 47 sec!
Without Take the previous results option: 44 sec.
Maybe other can share some light on this one....
Let's keep talking about this....