How to find preceding Document for Subcon delivery

Hi Gurus,

How to see the preceding document for subcon delivery. I have a subcon delivery but the document flow does not reflect any preceding document. I also checked in VBFA but there is no preceding document.

As a test, i created subcon delivery from one of the purchasing document using ME2O, but the delivery document does not reflect the preceding purchase document.

Is there any specific copy control settings for subcon delivery where i can check whether the doc flow check is updated or not or if there is any method pls suggest as it is urgent.

Regards & Thanks,

Ramesh