In Design Master Plumbing, you draw the 2D plan-view of your plumbing system, and the isometric riser diagram is drawn automatically. Any changes you make to the plan-view are automatically made to the riser.
One benefit is that you no longer have to worry about errors related to double-dimensioning. The pipe sizes in both the plan-view and the isometric are pulled from the database. When you change the size of a pipe, any labels in both locations are updated for you.