You can analyze the effects of variation of parameters / initial values using your own method with the use of an external DLL-function.
Ask Controllab Products for details.
20-sim provides a Scripting toolbox since 20-sim 4.4 that allows you to write your own automation scripts around a 20-sim model.
It is strongly advised to implement new customized multiple run experiments is by means of a script in either Octave/Matlab or Python.
The multiple run external DLL feature will be removed in a future version of 20-sim.