On the DWD Designer, click the Data Warehouse tab.
Expand Data Marts and Models to locate the data mart that will contain the model group.
Right-click the data mart and select New Model Group to open the Model Group wizard.
Specify a model group name and optional description. Click Next.
Select a data mart and click Next.
To create an new data mart, click New Data Mart. For more information about data mart creation, see Creating a data mart.
Click Next to list the available data marts in step 2.
At this point, the root node is automatically selected. Click Next.
Note:
In step 3 of the Model Group wizard, you can create additional model groups and arrange their positions in the tree using the arrow button on the right of the wizard.