Multi-pack item sales

Can you explain how this product would go thru the process from ordering to sale?  A multi-pack of 12 Chang beer. Let’s order 10 of these 12-packs.  Is there a report to give to be a shopping list for the buyer? When the buyer arrives, she leaves 8 in their 12-packs, but puts out 24 individual bottles for individual sale.  I assume the 12-pack has a barcode, and the individual bottles have a different barcode.  Now a customer can buy a 12-pack, or a single bottle.  How to make this work in aronium? 

Order / receive / split out to individual sale items / sell   Thank you.