Delivery quantity for each line item to allow to deliver as per customer

Hi Gurus,

Our client requirement is like this:

Sale Order Line Item Material Size Confirmed Qty Delivered Qty Actually want to deliver

10 X 600 1000KG 1000 2000

20 X 600 1000 1000 1500

In order to system to allow to deliver more than the actual confirmed quantity, I have given in Customer Master Unlimited Tolerance. But when he delivers, for the first line item 2000 KG then for the next line item it is saying only 0 KG of Material X is available. (even though Material Stock is available in MMBE).

How to map this scenario where, each line item should act independently, with out having impact of what delivered in the previous line item. Availability Check used is 01.

Thanks in Advance.

Best Regards

Sreekanth