Shapeways has published a simple but useful article outlining three common ways in which a traditional hand making jeweller could take advantage of 3D printing.
Shapeways Article – Three Ways Handmade Jewellers Can Use 3D Printing
They’ve covered most of the good points of using CAD/CAM for jewellery in plain language– the idea of building a virtual collection, the idea of not working at the bench, and the idea of testing models for fit. I would also add the advantage of sending files via email to manufacturers and factories rather than posting master models or moulds as well to their list, and letting them prototype the pieces on their end.
Of course, this does make the bold assumption that said jeweller can actually use jewellery CAD to produce their models.