Hi TW and George,
To let you know, i have made corrections at table level but root cause is still missing.
I found one sapnote no. 1080954 for the issue.
As per the note,
These problems occur occasionally and sporadically. In general, a cause cannot be determined.
In some cases, incorrect document flow records occur as a side effect of other database
inconsistencies between order documents and purchase order documents for third-party order
processing or individual purchase order processing.
If it is not possible to determine the cause of the problem, the only way to solve the problem is to
delete the VBFA entries that represent a reference between the order item and the purchase order
item that is incorrect or that does not exist.
So i believe there cannot be any RCA.
Still if anyone can give any random ideas, pl do.
thanks and regards,
Aayush Jain
SAP SD Consultant