Productivity KPIs

My company is currently using labor cost per pound as its primary KPI for productivity, this is well amd good but they are only looking at it within a given day which is then incentivising middle to upper management to push cleaning activities to non production days. This does not make any sense to me as we are then paying people time and a half to come in and do the work instead of doing it during the normal work week. Can someone please explain why this is would still be preffered or suggest an alternate KPI you have seen used in its place?