Allocating stock in an order to an existing PO

Seeing current and future stock levels of products and how many are coming vs how many are pre-sold/allocated per PO.

The main reason for the need for this is that we have on order at any given time up to 3-5 containers of stock from our front bar manufacturer. Very rarely do we have large amounts of stock on hand to assemble to order. It is often pre-ordered and we update customers on the arrival as containers get closer and then schedule in the packs depending on the order need. We would like to be able to allocate stock from an SO to an existing PO and it is stay allocated to it after the stock arrives and is received in.