Well in general you do but you don't. Some attribute fields in Teamcenter are linked to or based upon the item master, but the assembly is controlled via the PSE, (Product Structure Editor). If you keep the Database in synchronisation with the NX Assemblies you should not have any problems. To do this you need to do something like opening the assembly in the PSE, setting it to imprecise, open it in NX and save it, then go back into the PSE and set the assembly precise. At that stage they should have the same contents so any parts lists that you set up in NX Drawings should basically reflect the same information as the PSE.
It isn't based on attributes or reflected in other ways that I know of, but Teamcenter is big, so any other possible method somebody knows of would not surprise me.
