I have never tackled shipping (no one has asked me to), but I did block over-receiving and perhaps some of that can help:
But you’re right, you have several additional challenges that I did not. But you might use a similar trick for summing the total shipped qty, for example.
Mostly, though, I want to say this: I think this plan has some negative consequences.
So, the way I understand it, order is for, say 15 EA on 3 releases (5 per), and rather than ship the same thing 3 times on the same pack slip, your people ship 15 against only one of the releases.
Problem is that there are still 2 open releases creating demand and showing in Time Phase.
This is why we force our receiving people to never over-receive (at the release level). We (and the ERP) think there is still outstanding PO qty, when the supplier has no intent of ever sending more on that PO.
Conversely, you are possibly thwarting your customer’s efforts to separate these out into releases. I imagine there was some reason they didn’t order 15 on one line…
It always strikes me as odd, though, that there is no AR equivalent to the AP 3-part match. It’s not as important for shipping?
EDIT: I clarified this thought 
. I mean that our users cannot over-receive any PO release.
