To save the model with the old file name you can either select Save from the Application menu or click the Save button in the quick access toolbar. This will save the model in the same folder that it was opened from, with the same file name.
If the model has not been saved yet, the Save As dialog will open in which the location and file name of the model can be specified. If a model with the specified file name already exists, it is saved with the old file name.
If you want to save an existing model with a new name, select Save As... from the Application menu.
If there is a connection to the QPR BizArchitecture Server, choose File Model from the submenu. This will open a Save to File dialog. Note that only QPR Modeling Client administrators, model administrators, and users with at least view rights to all child diagrams can save Server models as file models.
Specify the where and under which name you would like to save the model, and then click the OK button.