kemal,
As part of ESS/MSS which services you are using, i mean wheather you are using WDAbap or WDjava??
-->If you are using the WDA services then you need to create the SAP_ECC_HumanResources sytem alias in the sytem landscape and
--> And you have to create the SAP_ECC_HumanResources$WebFlowConnector RFC destination in the NWA.
Regards,
Anil