ERP EhP5 marks a turning point for the architecture of SAP Employee Self Services. With the shift of the architecture of the ESS scenarios from WebDynpro Java to WebDynpro SAP architects need to reevaluate the architecture of their organization in this area.
Up to EhP5 the architecture of SAP ESS was quite clear. With most of the ESS services on WD Java a SAP Enterprise Portal was needed. This has changed now. With the new ESS you can implement them based on the Netweaver Business Client (NWBC) even without the SAP Portal.
In a nutshell you get three options for the future use of ESS:
1. WD ABAP-based ESS with NWBC without SAP NetWeaver Portal
2. WD ABAP-based ESS with SAP NetWeaver Portal
3. WS Java-based ESS with SAP NetWeaver Portal
A lot of information is already provided by some notes and by the documentation which also lists up all the improved features of the WD ABAP-based ESS:
Note 1450179 ESS Based on Web Dynpro ABAP available as of EhP5
Note 1509139 ESS EHP5 solution Based on Web Dynpro JAVA available
As a lot of SAP customers plan to implement EhP5 shortly or are just starting their ESS projects and are therefore defining their future SAP HR architecture.
The two decisive questions for your HR architecture:
Which version of ESS should be used in the future (WD ABAP vs. WD Java)?
Should we use SAP NetWeaver Portal for ESS or the NWBC?
I have tried to facilitate your work by listing up some of the decisive points:
1. Evaluation of the as-is situation
- Existing HR IT Architecture (if such architecture already exists it will contain a lot of the points listed below)
- Existing SAP HR systems within your organization
- Existing ESS implementations within your organization
- Implementations based on releases prior to ERP 2004 (based on ITS technology)
- Custom developed ESS scenarios
- Overall portal strategy of your organization
2. Determination of future requirements
- List of standard ESS-scenarios which should be used in the future
- List of requirements for additional ESS-scenarios:
- Scenarios which can be realized by using HCM processes and forms
- Scenarios which needs to be developed
3. Designing your future ESS architecture(s)
- Decision whether one unified ESS approach will be feasible throughout your landscape
The decision which ESS technology should be used within your organization will be made in this phase. The clear recommendation from an SAP’s HR architect point of view is to use the ESS WD ABAP whenever possible. The main reason which I could see against it is a very huge implementation of custom developed ESS scenarios based on WD Java. But even then it must be clear that future ESS functionalities will be based on WD ABAP.
Whether you use the SAP NetWeaver Portal or not depend on your strategic portal decisions and also needs to consider which other SAP scenarios you want to use in your portal implementation.
4. Designing your future HR architecture
A lot of strategic HR initiatives mean a lot of interesting activities for SAP architects. In some cases these activities create a very strong need for a HR architecture. In the past a clear architecture document for a SAP HR system was not always high on the priority list and substituted by a list of interfaces and SLA for the connected systems. With more and more customers adopting SAP ESS, SAP eRecruiting and SAP Enterprise Learning a clear document with architecture guidelines could save your organization a lot of redundant efforts which would be created otherwise.