IFERROR

Hey Anonymous ,

then that's not an error. You can check if it's blank to return the Usage Type and otherwise the lookup value.

Try the following measure:

Recommended Daily Usage Type =
VAR vLookupValue =
    LOOKUPVALUE(
        'Daily Usage Type'[Proposed Daily Usage],
        'Daily Usage Type'[PartPlantbyYearWeekNum], 'Master Data Hygiene (2)'[PartPlantbyYearWeekNum]
    )
RETURN
    IF(
        vLookupValue = BLANK(),
        'Master Data Hygiene (2)'[Daily Usage Type],
        vLookupValue
    )