Pick-to-light / put-to-light.

A lamp and a small digit display at every bin, cubby or carton position. Pick-to-light points at the location an item comes out of, which suits fast movers in a dense pick face; put-to-light points at the location it goes into, which is what drives a put wall or a store-replenishment rack. The operator presses the button to confirm, and that press is the only evidence the system has that anything happened. That is the whole trade: it is faster than reading a screen and hunting a shelf label, and on the pick side it takes away the barcode scan that would have caught the wrong item. The put side still starts with a scan, because nothing can name a cubby until the system knows what the operator is holding. Run lights with no verification scan anywhere downstream and pick accuracy is exactly as good as slotting, because a light confirms a location and never a SKU.