To add to what Doug wrote...

The stocking unit of measure must always be the lowest common denominator in which the item is ever counted, sold or bought. Where a carton is broken up it has to be CASE. Then an alternate unit of measure called CARTON is created with a factor of 12. Finally the selling unit of measure is set to CARTON. Doing this you can show on an invoice 6 CASES at $10.00/CARTON = $5.00.

The problem is that changing the stocking unit of measure once an item has been used will result in skewed sales history. But if you must do it, at least make sure that the quantities on hand, on sales order and on purchase order are all zero first.

Steve