Hi Senthil,
If there are so many different fields after executing this FM, system should send output to vendor for this change version.
Issue seems to be more compliated.
I suggest you set breakpoint at
class /SAPSRM/CL_PDO_BO_PO
method /SAPSRM/IF_PDO_DO_OUTPUT~SEND_OUTPUT
and debug the process of ordering the change version.
Meanwhile I suggest you check 'Output' tab in PO header level to see if output is generated but failed to be processed.
Hope this helps anyway.
Best regards,
Ivy