SAP UME Configuration
http://help.sap.com/saphelp_47x200/helpdata/en/8c/1024d16f350041917d01bfdaeb2fae/frameset.htm
Above is a comprehesive document about how to configuration SAP UME.
User Management Engine(UME) is used to manage user for SAP J2EE Engine. The UME has several persistency options for storing the user information, for example, you can use a database, an SAP system or a directory server.
If the UME uses an ABAP Engine for its persistency layer, then you use the SAP system user management transaction SU01 and role maintenance transaction PFCG for user administration. In this case, the roles you create using transaction PFCG appear as groups in the SAP J2EE Engine user management.
Before you can use UME to manage users, you need to configure it using an ABAP Engine for example. Several users are needed for the configuration.
SAPJSF is used as the communication user. This user is deliveried during system installation. Role SAP_BC_JSF_COMMUNICATION_RO is assigned to it.
J2EE_ADMIN must has the role SAP_J2EE_ADMIN to perform the J2EE administrative tasks.If you want to be the administrator, please assign this role to your user id accordingly.