Parametrically identifying 3D model(s) on drawings

This is something we've been working toward as well. 

We use the part number as the beginning of our model filenames. Engineers like to add some _description usually after, so we use a relation to extract the part number from the filename. Example: 123456_my_part.prt -> part_number = 123456

Our drawing formats then display that parameter in the title block. This generally works really well for simple cases where there is 1 model in a drawing, and the links work well in Windchill too. 

A big challenge is similar parts. Engineers like to control those with a table, and have a single drawing to define them. From the Windchill side, we require a WTPart to represent each Part Number so they can be used in BOMs. We link each WTPart to the model. The downside to this is on the change management - we use only 1 revision for the entire drawing, so if any part tied to the drawing is revised, everything must be revised. We keep the revisions the same across model, WTParts, and drawing.

In your diagram, I see you had a fixture example where multiple part numbers would be controlled all in the same drawing. You might want to investigate changing that to support  MBD/MBE. Ideally, each part should have its own drawing.