I'm just evaluating the new 6.1 version of OpenERP and the touchscreen POS module for its suitability for our three tiny retailing stores. I would say OE is terrific and satisfies almost all our requirements. Now, we have two questions.

1. We sell A ($1/item) and B ($1/item). In promotion, we set up a new product C for $2, which consists of one A and two B's. When we sell one C, we want the inventory of A decreases one and the inventory of B decreases by two automatically. How can we implement this?

2. For quantity discount, we setup a product D, which is one box of A's, and sell it for $10. When we sell one D, we want the inventory of A decreases by 12 automatically. How can we implement this?

Any help is greatly appreciated!

You could look at using kits rather than BOMS. Say
product 1 = kit comprised on 1 x product 2 and 2 x product3
when you sell product1 the moves created are for product 2 & 3.
I am not sure if this will work exactly right in a retail environment, but your invoice print could be changed to reflect what is actually sent or left as product 1.
Same logic for your second case.

Kevin, I greatly appreciate your suggestions. Will learn kits and have a try.