Pick a date range. Each stage bin (weld color lines + Powder and Final Assembly) shows the parts it consumes (routed by CODE_SORT) for the trailers building in range (production calendar), vs what's staged in the bin. Sub Assembly is different: it shows the components needed to build the subs work orders the subs schedule picks for trailers due in range, vs what's staged in the sub-assembly cells (SUBS + SUB2). A shortfall on hand elsewhere is a transfer from the main warehouse; one that's nowhere is truly short.