Comment 36 for bug 610738

I have 10 products at average cost of $10.
I buy 10 more products with average cost of $1.
I return the products at average cost of $5.50 but actual cost of $1 (the credit I receive). Where has the $4.50 gone?

I made profit without doing anything but fiddle some papers - clearly wrong (I may have got example back to front but principle holds).

Although reverse case is possibly a very good way to beat your tax bill and increase assets at same time it will sadly will put me in prison. Prison for following OpenERP's version of average costing seems harsh.

It seems every bug about average costing (and there are more than this one) is met with a won't fix, wait till next version and a wikipedia reference. Like Kevin, total rewrite of anglosaxon, plus stock just to make work - plus needing to use c2c picking_invoice relation addon to keep it all straight.

OpenERP I hope you can understand why this is a very real bug.

When you return to supplier, you are sending the COST. When you sell to customer you are sending the PRICE. Therefore you are not returning AVERAGE cost - you are returning ACTUAL cost and must adjust average cost accordingly to reflect this. Putting up Wiki entries that deal with average cost sales is not helpful in a discussion on returns.

However and importantly - when you take a return from a customer you are receiving products not at AVERAGE cost but at the original ACTUAL sale cost. Therefore average cost needs adjusting. If this is not the case - you have another bug. If this is the case then you have proven yourself that the current supplier return behaviour is wrong. Whenever you increase or decrease inventory by a KNOWN cost you must adjust average cost.