WHERE="Activity.GROUP_ID = VoGroup.VO_GROUP_ID(+)
AND Activity.SPECIFIC_TO_WBS_ID = Wbs.WBS_ID(+)
AND Activity.VO_PERSON_CATEGORY_ID = VoPersonCategory.VO_PERSON_CATEGORY_ID(+)
AND Activity.UNIT_OF_MEASUREMENT_ID = UnitOfMeasurement.UNIT_OF_MEASUREMENT_ID(+)
AND Activity.PARENT_ACTIVITY_ID is not null"