Hi,
If its external service, system will automatically generate PR from the WO and you have to convert it to PO. Once the service is completed, you can create / accept the SES. As of my knowledge, there is no option in standard to create SES from IW41.
Refer the thread: External services confirmation- ML81N vs. IW42?? | SCN which explains the concept.
Regards,
AKPT
