If you are in the prepare replenishment screen a line item will not show up as Qty on Supply if an SO is linked to a PO for that item.
In my case I link SO transfers to PO’s for all or some of items I know will have to be shipped to our satellite offices once it comes in. The problem comes in if you were to check the Prepare Replenishment after that, it does not show any of that item as Qty on Supply or at least until the SO is posted.
To me it seems logical that the Prepare Replenishment should still show an item as having a Qty on Supply even if there is an SO for that item.
If this topic has already been discussed let me know and I will check it out.