There needs to be a way to record tracking information of purchasing shipments to address drop-ship tracking. A customer requests equipment, I create a Sales Order and a corresponding Purchase Order for drop-shipping. I can't "ship and invoice" the Sales Order until the Purchase Order is "received and invoiced", and there's nowhere for me to record shipping information about lines on the Purchase Order. I need to be able to tracking per line as items ship at different times, and I need to be able to access that information for notification purposes so I can notify technicians or other relevant personnel that an item was shipped by the vendor and that they should expect it at customer's site on such-and-such a date so they can either schedule a visit or notify the customer to watch for arrival. This could be addressed by adding a shipping agent, tracking number, a ship date, and (estimated) arrival date to each PO line.