Accounting for product breakage or loss
If you need to record a reduction in stock due to breakage or other loss, the best way to do this is to add a manual Inventory Adjustment. For the quantity, ensure that you record this as a negative number (i.e if you lost 3 items, you will want to record -3 in the adjustment).
It is recommended that you also categorize the adjustment as this will allow you to see your total material costs in loss for a certain time period via the Product Adjustment Report.