Architecture of ESS:
ESS environment consists of a frontend and a backend system:
- The ABAP (R/3) system is the backend system. It contains HR master data and ESS related backend code and customizing.
- The JAVA system is the frontend system. There are several applications running on the JAVA system. The Portal is one of these applications. It is used as a single point of entry. The portal can call other applications and display them inside of iViews. These iViews are quite flexible and can call different things. For WD JAVA based ESS this means that they will call WD JAVA applications deployed on the same JAVA system. Although this applications can be called seperatley they are designed to be used inside the portal and be structured via 'Home Page Framework'
The communication between frontend and backend is done via Java Connections (JCO). It is a method of RFC communication between ABAP and JAVA.
In general you need a working R/3 and a working Portal landscape. From HR point of view for using ESS you need:
- SAP HR and EA_HR package in the backend system
- ESS application package in JAVA area. It contains the JAVA applications deployed on the JAVA machine (depending on your version e.g. ESS 603).
- FPM application package in JAVA area. It contains the JAVA applications deployed on the JAVA machine (depending on your version e.g. PCUI_GP 603).
- ESS Business package. It contains roles, worksets, pages and iviews. This is the portal customizing to know how the services (which are deployed via the application pacakges) are called in the portal.
Home Page Framework:
The HPF is a configuration to navigate to the final service using other ESS services. The screenshot below shows the area group page, which is actually a web dynpro JAVA service itself. However the only idea is to use it to navigate to other services.
ESS Homepage (Area Group page)
The customizing for the HPF can be done in the R/3 system, as the WD JAVA services uses this data via JCOs. The below grapic explains the connections:
Architecture of ESS