The Credit Memo cancels the invoice, it reverses both the accounting and the inventory transactions. One document that fixes everything. But, what if you don’t need the whole package? What if you just want to cancel an invoice without influencing inventory? For example, a customer reported about damaged goods. You need to credit the customer but the damaged items will not be returned to the warehouse. For such scenarios you can copy the invoice into a credit memo and set the line of the relevant items to be “Without Qty Posting”. As a result the customer is credited and the items are not returned to the warehouse. Using this option allows keeping the paper trail of the specific deal, and maintain transparency.
This option is available in both A/R and A/P Credit Memos and is available in SAP Business One, version for SAP HANA and SAP Business One.
Source: Ari Schapira | SAP Business One – The Tip of the Week