New Project
To start creating a new project with RS3, select New Project 
from the toolbar or the File menu. A new blank project window will be opened, in which you can start creating your model.
Before you start entering your model boundaries:
- Select Project Settings
from the toolbar or the Analysis menu. Various analysis and model parameters are set in the Project Settings dialog. In particular, if your model is staged, you should set the Number of Stages before you proceed further, as this affects the availability and operation of certain modelling options. - See the RS3 Quick Start Tutorial for a lesson on how to create a simple model with RS3.
When the RS3 Modeler is first started, you will always be presented with a new blank project window named "Project1". You can immediately start creating a model in this window. If you are not starting a new project, then simply close this window, and Open the file you want to work with.