You want users to log onto back-end systems with a different user ID from the user ID they used to log onto the SAP NetWeaver Application Server (AS) Java. Possible reasons for doing this include:
User Mapping enables you to map AS Java users to back-end users. User mapping is a form of Single Sign-On. Users do not need to authenticate themselves again when applications connect them to a back-end system.
When applications connect to a back-end system, they rely on a specific infrastructure to provide them with the connection or the connection information. When you configure user mapping for an application, you must know what infrastructure the application requires. The user management engine (UME) supports the following infrastructures for user mapping:
To determine which infrastructure your application requires, refer to the documentation for that application. Otherwise you can assume that if the application was installed with a portal it requires a portal infrastructure. Likewise if the application was installed without a portal, you can assume you require only the AS Java infrastructure.