There is a check box on the sales order header called Ship Complete that isn’t abled to be selected in a standard sales order. It’s used when the call center functionality is turned on and it acts as an option to provide an indicator that the customer doesn’t want to receive partial shipments. This is a quick walk through of how this works.
Now it would be nice if this worked without having to use the extra call center setup. Another thing would be nice is the check would also check the order reserve instead of the full physical reserve. This would be helpful in scenarios where you create the PO to bring in new inventory so you can reserve off the incoming PO you can still do this but the ship complete message won’t check this and so you will get an error message if you try to confirmation of the order to the customer. So likely some tweaking might be needed to improve the process.