You have prepared an Invoice with a list of Products ordered in various quantities.
You start shipping products as soon as they are ready, i.e. it takes several shipments to deliver all the ordered products.
You can create a Packing Slip from the Invoice. When a shipment is ready for delivery, edit the Shipped Quantities for each Product included in the Shipment, and print out the Packing Slip.
You can now also track Previous Shipments:
Each Product in the Packing Slip includes a “Previously Shipped Quantity” field which keeps track of the number of items already shipped.
After the first shipment, whenever you update the Shipped Quantity of a Product in the Packing Slip, the Previously Shipped Quantity field is automatically incremented by the previous quantity shipped. (Note: this is subject to your prior confirmation via a popup message).