FIFO / LIFO - Add Products - better stock and cost tracking

Often you'll buy the same inventory over the year but the cost of each batch may differ.

They would be sold under the same item number but since each batch might cost a little different, there needs to be a way to track the cost of each batch as it is sold out.

Thus, if you have 3 batches of shoe laces, you might have something like this:

Batch 1
1,000 brown shoe laces
Item Number: 12345
Cost: $0.50 each
Date: 01 Jan 2011

Batch 2
1,000 brown shoe laces
Item Number: 12345
Cost: $0.51 each
Date: 01 Feb 2011

Batch 3
1,000 brown shoe laces
Item Number: 12345
Cost: $0.52 each
Date: 01 Mar 2011

As you can see, the cost increased with each batch but you might be selling them all at the same price.

A neat feature would be to sell the products where you can choose FIFO (first in, first out) and thus draw from the first batch first and have that cost tracked too, and then the second batch, third, etc. This way, you might be able to generate a very accurate report of your inventory and costs.

ADV Profit Module have average product costs method, check here:
http://www.opencart.com/index.php?route ... n_id=16601