How to understand and prepare for migration to SAP S/4HANA?

How to prepare ?

We propose an initial answer through 4 questions that should be asked:
 

The question is crucial because there are indeed a fairly large number of restrictions that prohibit migration to "S/4HANA":

• Not all initial versions are directly convertible to the solution.
• A minimum level of Support Package is required
• "S/4HANA" is not available in all vertical solutions (Industry Solutions)
• The activation of some Business Functions makes it impossible to migrate
• Some add-ons are not compatible with "S/4HANA"
• Etc.

SAP provides several ways to verify the eligibility of your system:

• OSS notes (e. g. OSS Note 2491467 - SAP S/4HANA 1709: Restriction Note)
• Tools, such as Maintenance Planner which is a Cloud application connected to your system and Simplification Items-Checks which is installed on your system by our OSS rating. These tools allow you to screen your system and verify its eligibility.

The system to be migrated must be Unicode. If this is not the case, a Unicode conversion must be performed before migration to SAP S/4HANA.

The system to be migrated must be an ABAP-only AS. In case of Dual-stack systems (AS ABAP and AS Java combined) a split must be performed before conversion. "S/4HANA" requires the implementation of an SAP NetWeaver 7.52. The following AS for JAVA instances are compatible:

• Adobe Document Services
• Enterprise Services Repository
• Advanced Adapter Engine Extended

Finally "S/4HANA" requires the installation of an SAP NetWeaver 7.52 front-end server.
 

The most important factor in accelerating migration and reducing downtime is the volume of data. The more important it is, the longer the Downtime and therefore the migration will be. SAP provides a tool called SAP Data Volume Management Work Center (DVM WoC) in Solman to enable:

- Identify the data that can be reduced (Guided self-Service)
- To simulate the gains that will be obtained by reorganizing or compressing the database (Reorganization and Compression)

These actions can be carried out before and after the conversion. But they only make it possible to reduce the conversion time if it is carried out beforehand, of course. The other acceleration factor is preparation.

4) So, how to prepare for migration?
 

First of all, by checking the eligibility of your system and the technical prerequisites and by ensuring that the human and material resources are available to carry out the project.

Then by launching the following preparation actions:

• Analysis of the specific Code via a tool made available by SAP called Custom Code Analysis and evaluation of adaptation effort
• Evaluation of the sizing of the target database by executing the report /SDF/HDB_SIZING. It should be noted that as a prerequisite for this action, a certain number of OSS notes must be implemented on your current system
• Extensive functional preparation (identification and prioritization of processes, writing and validation of test scenarios and test sets)

Once these preparation actions are completed and the Brownfield approach (Migration) is validated, it is advisable to launch the project quickly because the longer you wait, the greater the migration effort to SAP S/4HANA will be. Indeed:

• On the one hand, SAP will continue to evolve its solution and widen the gap with your current solution
• On the other hand, your system will also continue to evolve, covering a larger scope, which will lead to a larger volume of data to migrate and a greater testing and training effort during the transition to "S/4HANA".

We recommend that you carry out a technical POC that will allow you to test the migration in a Sandbox environment (i.e. without risk) in order to validate its technical feasibility and prepare you as well as possible for the future project while making it secure.