Sometimes, CAD designs include subassemblies of parts for the purpose of organizing those parts as a group, rather than as an assembled structure. An example would be a set of parts that are gathered as a group during the manufacture of a higher-level assembly; sometimes referred to as a phantom assembly. The CAD structure and Windchill product structure association and build actions create a Windchill part for this subassembly to parallel the CAD structure. However, as the subassembly is not a true assembly in and of itself, it has no place in the final BOM.

Windchill supports filtering these gathering parts from the BOM using a Gathering Part attribute on the Windchill part. When the Gathering Part flag is set to Yes, it indicates an object that can be filtered from the BOM. There is no other impact resulting from setting this attribute, including no effect on the gathering part’s related CAD document.

To assign a gathering part attribute to a Windchill part: