Create a list of QR codes for each order delivery method and order status. For each of that you can select if you want to notify customer of the status change with email or other.
For example: You have 2 shops (LA and Copenhagen) and 2 delivery methods (pick-up and delivery to the client’s home).
You will have a QR codes On each invoice. Once your driver pick up the item from warehouse he scans QR code, then the status of an order changes in back-end and you can see the changes live.
From the other side your client receives email that his item is being delivered to the shop or his home.
Once your driver delivers item to the client - he scans the final code (Well done! - on screenshot) and the order get the status as delivered. And the order status could not be changed anymore.
And here comes one more marketing possibility: if the curious client will scan QR code after the order was closed - he will be moved to a page with offer to get 10% (on screenshot) discount on new order that will increase future sales.