Yes.  As long as you’ve set up your Budget Groups carefully, the modeling steps (Steps 5-8) can be done before, after, or simultaneously with the classical budgeting steps (Steps 9-10).  Use your Budget Groups to help you stay organized and keep careful track of which G/Ls are being worked in each step.  You’ll also need to coordinate any adjustments to your Budget Controls to make sure the proper G/L types are opened or closed at the appropriate times.