Switch to S/4
S/4 Hana transition - well prepared is half the battle
The switch to S/4 Hana is a demanding, multi-layered project in which a wide variety of aspects have to be taken into account, especially with regard to the SAP basis. As everywhere, however, the better the preparation, the smoother the changeover. Therefore, the first step is to analyze and take stock of the SAP landscape and existing SAP monitoring data for dimensioning the target architecture (sizing), considering add-ons or in-house developments (code checking) and subsequent operation.
The front-end strategy should be clarified in advance. In principle, it is possible to use SAP GUI, but SAP Fiori is already mandatory for some SAP functions. And the method of migration also needs to be well thought out: system conversion (brownfield), new implementation (greenfield) or mixed model (colorfield) - which method is the right one depends on the individual case.
Conversion or Greenfield
If you want to keep individual extensions and add-ons and are satisfied with implemented processes, you should choose the system conversion. It takes place in a big bang with only one downtime. Greenfield implementation and the complete reconstruction of the SAP landscape, close to the SAP standard, are more complex and time-consuming, also because S/4 Hana only goes into operation step by step. This is recommended for companies that want to benefit directly from SAP innovations and/or gradually replace their multi-ERP environment (SAP/non-SAP).
When a decision is made in favor of a system conversion - experience shows that this is the majority of existing SAP customers - some preliminary work must be done. At the latest, the existing SAP system must be migrated to the Hana database and converted to Unicode, Adobe Document Services (ADS) must be provided for the new output management, and data that is no longer required must be archived (housekeeping). The Hana database and the application servers (RAM, disk space, CPU) must also be designed to fit exactly, code checks must be carried out for add-ons and in-house developments, and much more.
Choice of the operating model
Then the question of the future operating model for SAP S/4 needs to be clarified: On-premises, private or public cloud, hybrid? The decision depends, among other things, on the legal requirements for data storage, the requirements for service level agreements (SLA), or the need for 24/7 operation with a service desk from an SAP provider.
If you want to retain control over IT infrastructure, hardware and networks and/or work with particularly sensitive data that must not be allowed to leave your premises, you used to operate on-prem in your own data center. If the focus is on agility in terms of developments and smooth digital processes, with dedicated service and response times (RTO and RPO), a secure private cloud architecture on scalable and highly available hosting infrastructure platforms is the best option.
For companies that want to network their SAP users across locations and benefit from short latency times and scalable computing power, S/4 operation in the public cloud (GCP, Azure, AWS) comes into consideration. When selecting a hyperscaler, you should be guided by certifications and quality seals, the existence of local branch offices and data centers, and the maximum time required to process and resolve an incident.
Do not forget security
However, security must not be neglected, especially the adaptation of SAP authorizations and roles in the course of the change. Here, the use of SAP identity management in conjunction with an add-on is recommended, in which the assignment, administration and revocation of temporary privileged authorizations or emergency roles (firefighter solution) can be carried out in a standardized, automated and legally compliant manner.
Ideally, the reliable and high-performance operation of the S/4 landscape is always ensured by an SAP monitoring solution that automatically monitors in real time, clearly displays the current status and notifies immediately. In this way, vulnerabilities and SAP security gaps are also detected immediately and can be closed without delay.