Hi Andy,
There is a VB sample shipped with Inventor that
will update existing members of an iPart factory.
You can run this as a batch process when you modify
the factory.
I don't have access to it right now, so I can't
say exactly what it is called.
Hope that helps.
Tom Sturtevant
Inventor Part Modeling
Tom Sturtevant
Inventor Part Modeling Developer
Autodesk, Inc.