Hi Pavan.
The Solution is as follows:
Step 1:Make sure your delivery order has been processed after PGI and note down your delivery document number.
Step 2:Go VTFL.(copying control for delivery doc to billing doc).
Step 3:Go to Table View (Menu).Click Display=> Change.
Step 4:Now Select delivery to invoice Ex:billing type:FI & Delivery type LF and click on Item under Dialogue Structure.
Step 5:Select your Item Category from the list.Double click on it.
Step 6:Enter Data VBRK/VBRP :003 (if you r processing a single invoice) or other values as required.
Billing quantity:D(for delivery order related billing) or other values as required.
You can edit other fields as per your requirement but the above ones are most important for delivery to invoice processing.
Step 7:Save it.
Now go to VF01 and create invoice w.r.t. delivery.
Regards,
Sap Droid