Two examples of key topics in this step are the Unicode conversion and ensuring an archiving concept is in place. While Unicode conversion is a mandatory task to be completed before moving to SAP S/4HANA, you can run the conversion without caring about archiving.
From our experience Unicode conversions are already completed in most of the ECC systems. But if not yet done, you should plan for it immediately in order to make sure you finalize it before your conversion starts.
Regarding archiving systems, we still see there is a remarkable number of especially smaller systems running without archiving concepts in place. In order to target the right-sized SAP HANA-system for your SAP S/4HANA it makes sense to look into archiving. It also makes sense to do that independently from your conversion project and ideally well in advance.
Decoupling these activities from the real technical conversion gives you the freedom to concentrate solely on the limited number of technical conversion steps in your conversion project. You can also run the custom code conversion for SAP HANA-readiness outside your SAP S/4HANA conversion project. No matter if internally or outsourced to a partner – preferably by near- or off-shore resources – working through it in parallel and steered by a local development head, the vast majority of this preparation work can also be done outside of your conversion project.
Following the described approach there is not that much left to be done in a conversion project: Asset Accounting, New General Ledger and Material Ledger can be switched on in a technical sense without much effort (and for now with limited benefit) just to make the conversion possible. The value resulting from possible process improvements with those components can be generated at any time after the conversion of the productive system.
The business partner is a central component in S/4HANA and needs to be implemented as well. Also, at least some minor adjustments in the authorization concept – e.g. in the Fiori area – need to be considered.
In any case, it is highly recommended to test these remaining conversion steps in a sandbox system. Converting the sandbox, which is a copy of your current productive system, allows you to:
The conversion of the productive landscape is done after intensive testing of the processes in the sandbox. With this approach the productive conversion really only is a technical conversion that needs to be done on your productive landscape: development, quality and production.
However, in complex system landscapes there are of course additional steps to be considered. Transformation of the whole landscape when having more than one ECC system adds complexity, e.g. regarding system and master data harmonization – nevertheless the described structured approach is still valid in general.