Using Performance Modeler we can add dimension to an existing cube without rebuilding it.
Double click on the cube.
Drag and drop the dimension from list to cube area or right click the dimension and select ‘add dimension to a cube’
The result appears as follows:
Select what should be done with any existing data in a cube from options below:
• placed to a single member in the new dimension.
• duplicated for all members in the new dimension.
Result: dimension added