We have mass migrated EPMBuildRule using WBM from a non-Windchill source system. But after CAD visualization was completed viewables were not available on the associated parts. Please see cases 12585734, 12553643, 12587243. We have been informed that EPMBuildRule doesn't create the full association Windchill needs to build the parts. This should be enhanced because there is no tool post migration to perform the mass build.