When ever a user account(FND User) is created , it is created as user in Workflow Directory Services (WF DS) table WF_LOCAL_ROLES with user_flag as Y. If a new responsibility(FND Responsibility) is created it is created as role in Workflow Directory Services (WF DS) table WF_LOCAL_ROLES with user_flag as N.
If you assign a responsibility to a FND user, an entry is created in WF_LOCAL_USER_ROLES which means the workflow user is assigned a workflow role.
More detailed information Oracle Workflow Directory Service
In WF_LOCAL_ROLES table
FND Users will be created with USER_FLAG as Y
FND Responsibilities will be created with USER_FLAG as N
In WF_LOCAL_USER_ROLES table the associations between users and roles should be created.
Let us consider following example
FND Users: SMATT, MSPENCER, MKING
FND Responsibility: Shipping Manager
SELECT user_flag FROM wf_local_roles WHERE name IN ('SMATT', 'MSPENCER', 'MKING');
This should return Y for all three users.
SELECT user_flag FROM wf_local_roles WHERE display_name = 'Shipping Manager';
This should return N for the responsibility.
SELECT user_name FROM wf_local_user_roles WHERE role_name IN (SELECT name FROM wf_local_roles WHERE display_name = 'Shipping Manager');
should return all the users who are assigned the Resp HR Manager.