Deterministic - Select this button to set the simulation mode to run a deterministic simulation
Probabilistic - Select this button to set the simulation mode to run a probabilistic simulation
Sensitivity analysis - (Sensitivity Analysis Toolbox). Select this button to set the simulation mode to run a sensitivity analysis.
Scenarios - Select this button to run scenarios (deterministic/probabilistic/sensitivy analysis as selected above).
Run, F12 - Runs a simulation for the current project. Note that the model must be free of errors for this button to be activated. Refer to the Errors window.