Dr.,
You can use 2 data sources in the Model.
1. The data source with the ID. This will be the only Dimension and Category.
2. The data source with the Measure AND the corresponding ID. The ID is required so that the measure relates to the Dimension/Categpry. Simply drag the Measure field into the "MEASURES" window. (*NOTE* The ID in both data sources must be identically named)
That will give you a simple Cube......1 Dimension, 1 Measure.
I hope this works for you.