Vendor - Subcontractor - Customer Direct Shipping


Need your expert advises on a small issue. The scenario goes like this

There's a vendor who manufactures the product after the order is placed by us. The vendor then directly ships to a subcontractor for some additional work and once the processing is done, the subcontractor ships directly to our end customer. The goods are not received by us physically at any point of time. We invoice the end customer upon goods receipt.

Could you guys kindly propose a method to track the above process on SAP in accurately keeping stock records to aid accurate invoicing.

Thanks in advance!