Use the following procedure to create a new blank model file.
Tip: You can also create a new model file by copying an existing model file with the Save As command. For more information, see Saving Models.
From the File menu, choose New, or press CTRL+N (Windows) or ⌘+N (Mac).
A new blank diagram will open in the Stella window. Any models you had open will stay open.
Now you can start building the model and you can save the new model.