Hi Dau,
Did you have a look at Sales BOM functionality?
http://help.sap.com/saphelp_erp2004/helpdata/en/dd/560234545a11d1a7020000e829fd11/content.htm
"Processing at Component Level
If you want the system to carry out pricing, inventory control, and delivery processing at the component level, enter LUMF in the Item category group field of the Sales: sales org. 2 screen in the material master record of the finished product. In this case, only the components are relevant for delivery. During processing the system automatically creates a delivery group. The latest delivery date among all the components becomes the delivery date for the entire delivery group."
Regards,
Szymon