Hi,
Same problem 
.. I tried also adding this to the condition, T2.[Quantity] > T1.[OpenCreQty] where the Delivery Qty must qualify against Open Qty. But still it accepts deviation.
IF @transaction_type in ('A','U') AND (@OBJECT_TYPE='15')
BEGIN
If exists (SELECT T3.docentry FROM ORDR T0 INNER JOIN RDR1 T1 ON T0.DocEntry = T1.DocEntry left join DLN1 T2 on T2.[BaseEntry] = T0.docentry and T2.[BaseLine] = T1.[LineNum] INNER JOIN ODLN T3 ON T2.DocEntry = T3.DocEntry WHERE T2.[Quantity] > T1.[Quantity] and T2.[Quantity] > T1.[OpenCreQty] and T3.DocEntry = @list_of_cols_val_tab_del)
Begin
SET @error = 10
SET @error_message = 'Not allowed to deliver more than SO quantity'
End
END
Thanks for your help..
Fernz