Open Order Quantity for open sales orders
Is there a standard SAP Report that gives the open order quantity for every open sales order. "Open" is defined as any order quantity that has not shipped. Delivery creation is not the same as shipment. VA05 Report does not contain enough information to calculate the open order quantity for an ERP-based backlog report.
Try VA05 schedule lines standar variant...include status fields and both ordered qty and confirmed qty. In SAP standard system order status, status A means open orders fully (Nothing shipped, everything opened). Status B means in process orders (Partially processed - shipped). Status C means complete orders (Nothing opened). As there is no delivered qty in VA05, you need to download to excel the file and calculate the difference between both qty fields for each A and B status. That is a way to get the missing qty to be delivered or open qty as you stated.
Hope it helps.