HI Kyung, I think I got the solution. The only way to ignore the error message "No business partner determined for customer &1" (Message class: FDM_COLL_01, No: 014) is by suppressing the error message in table T100C. The badi checks whether the message is E or -(Suppress). If it is E then it will record in the log and if it is -(suppress) then message is ignored.
Do you know what could be the complications if we do so ?