A "Mass" attribute is created for the "Physical Product" object class. The attribute is "mapped" with the CATIA V5 attribute

Mass <-- sys:Mass. In this case, the attribute was mapped for CATProduct AND CATPart. If you remove the mapping for the CATProduct, you only get the masses for parts, but the assembly has 0 g.

Is there a better way to configure this? Is it possible to create attributes only for CATPart or only for CATProduct?