Hi Krishna,
Check this doc it may be helpful
-->If you are using the webdynpro ABAP services for ESS, you have to create the system object which connects to the backend system and and have to Register the system object in the path
system Admin-->system config-->create New .--->click on Reregister.
-->You have to create the xyz$WebFlowConnector destination in the NWA for UWL.
Hope it will help you....let me know if have any doubt
Regards,
Anil