Add return workflows to book

[neilt]

From matrix discussion. Should be added to workflows.

There can be 3 types of returns:

1. Returned like new - Item can be restocked by adding back quantity and COGS, then crediting the customer.
2. Returned, but worthless - As CornerCase explained, completely written off, in which case the inventory quantity and COGS should be tracked to an inventory loss account. This account should be different than losses from physical inventory and cycle count losses.
3. Returned, but cannot be sold as new. This is really a different product, so the change in COGS should be written down and the write down put in an inventory loss account. The new product should have a new part number, new COGS and new sales price.

That is how we would do it now - just to make sure im understanding the question - customer has bought product xxx for $150 and paid for it and then someone has realsied its on sale for $120... so we would create another invoice -1 xxx at $150, +1 xxx at $120 - net result is $30 refund - no change to inventory levels and cogs remains the same (as the one we stuffed back at the front of the FIFO queue gets applied to the second line? if that example fits your thinking, then yop thats exactly what we do manually