After going through your requirement of "part standardization system", I think I might not be totally wrong in suggesting you to try by creating folders in EPDM based on the categories identified (atleast at the category level). You can later work on defining variables as needed.
The folder creation based on the categories identified will be one time job and could be an admin task. But once you do it, you can have documents (once created and stored) automatically categorized under the defined folders.
I hope you would now be thinking ' IS IT NOT CRAZY to do so..!!!"
Do you remember that SolidWorks "TOOL BOX" and similar standard part library structures which are typically maitained to contain different sets of documents in an organized way and intelligently....
If not let me know the hurdles that might come up and which I would have missed to consider..!!! Let me know if this information helps