Hi Hyongwoon,
Central user is not just require to communicate with MWS but user on MWS can access IS. In an organization where Active Directory is configured and if any AD user need webMethods access then MWS is configured to connect to AD and add AD users to MWS user database then using central user management we connect to MWS user database and give access to AD user to login to IS.
How do we all this in MWS and IS is better described in IS Admin guide.
#webMethods-BPMS#webMethods#MWS-CAF-Task-Engine