Hello Sumer,
It seems to me that you are mixing two concepts.
DMS -> Is used to store documents, for example it can be a production drawing, which is required for assembly on the shop floor.
PRT -> Is a production resource tool, is a move able operating resource and not a document, an example can be a shared drilling machine. Also PRT is relevant for capacity planning where as DMS is not. Documents can be linked to a PRT.
DMS and PRT may be linked in the same way to task lists or production order operations, but they are different from each other
I hope I was able to clarify your query, if not please revert.
Best Regards,
Ameya B.