From SAP ERP 6.0 to SAP S/4HANA in Four Steps
You can migrate to SAP S/4HANA using the standard migration paths. For those already running SAP ERP 6.0, a system conversion is the correct method.
SAP S/4HANA is the next generation of the SAP Business Suite enterprise software from SAP. Based on the SAP HANA in-memory platform, SAP developers have carefully tailored the solution to meet the needs and challenges of the digital economy. Not only can companies optimize existing processes, but they can now also realize new processes to assert their advantage in the digital competition.
The migration to SAP S/4HANA is therefore not a one-off project such as an upgrade or database migration. Instead, it involves the entire IT system landscape. Enterprises should always plan the transformation in terms of their optimum future SAP target architecture. This makes life much simpler for users: Thanks to the holistic nature of the transformation, it allows often complex and heterogeneous IT system landscapes to be eliminated (unlike a pure migration to SAP HANA), laying the foundations for simpler, more streamlined processes.
Three Paths to the Destination
As with the SAP Business Suite, enterprises can choose from three possible methods for migrating to SAP S/4HANA: greenfield, system conversion, or landscape transformation. In assessing which path is the right path, the target architecture alluded to above is very important (more on this topic later in the first article of our series “SAP S/4HANA: Chart the Route for Digital Transformation”). Companies that are already running SAP ERP 6.0 (enhancement package 0 and higher) can migrate directly to SAP S/4HANA with a system conversion.
Which path is the right path for my company? A decision matrix illustrates the various paths for migrating to SAP S/4HANA.
In technical terms, a system conversion to SAP S/4HANA retains the system ID for Customizing, development, data, authorizations, and interfaces. This is also known as in-place migration. For systems running SAP ERP 6.0 enhancement package 0 and higher, companies can migrate directly to SAP S/4HANA without having to upgrade to a higher enhancement package. This assumes that the system is already a Unicode system. Following the release of SAP NetWeaver 7.5, SAP only supports Unicode systems. If a company’s system is not Unicode, it must be converted to Unicode before the conversion. The actual system conversion to SAP S/4HANA is supported by the SUM-DMO, the Software Update Manager with Database Migration Option. This helps companies upgrade and migrate databases in one step, meaning just one period of downtime.
Readiness Checks Pave the Way for the Migration
To ensure the migration is successful, companies need to adjust their IT systems to meet the framework requirements of SAP S/4HANA during the system conversion. It is best to analyze the required adjustments in four steps. This “readiness check” for SAP S/4HANA should be performed as early as possible to obtain an overview of possible adjustments. These preparatory measures can then be analyzed during live operation where applicable.
Step 1: Maintenance Planner
The Maintenance Planner checks an organization’s business functions, industry solutions, and IT system add-ons. If the check does not produce a valid conversion path (for example, because an add-on has not yet been published), the Maintenance Planner prevents the system conversion because no stack XML file can be generated. In this case, the relevant partner should be contacted to find out when the add-on will be released. For sandbox system conversions, it is possible to create an exception to continue the system conversion without an add-on release.
Step 2: Simplification List
At a functional level, the simplification list provides a detailed description of how SAP S/4HANA will impact the individual transactions and solution functions of the SAP ERP system. If this list shows transactions or functions no longer exist, this does not mean that certain functions will be lost. Instead, these functions will be merged with other elements or reflected in a new solution or architecture.
The individual objects of the simplification list are dependent on the current SAP S/4HANA Feature Package Stack, and can be grouped into the following categories:
- Changes to existing functions
- Functions no longer supported
- Functions that are no longer strategic
At present, numerous objects of the simplification list can already analyzed using pre-checks (see the next step). Other automated processes to determine whether simplification objects are relevant with regard to customer-specific system usage are currently being planned. It is worth noting that not all points are relevant for a system. Instead, the effort required for the conversion should be determined for the relevant points.
Step 3: Pre-Checks
Pre-checks review the system settings that are required to perform the actual system conversion. These are available to customers in the form of SAP Notes, and can therefore also be used in step 2.
Step 4: Review the Customer Codes
One of the most important features of SAP S/4HANA is the simplification of the data model. SAP provides compatibility views for tables that are no longer required in the migration to SAP S/4HANA. SAP also provides a check tool based on SAP NetWeaver 7.5 that checks necessary adjustments, for example adjustments required for field length extensions. The SAP S/4HANA simplifications can be imported in a file, and compared with a code extract of the SAP ERP system. A list is created showing the reviewed customer code and indicating any code that needs to be changed to make it compatible with SAP S/4HANA. There are plans to fully integrate these checks as a check variant of the SAP Code Inspector in future. The tool currently supports checks of the adjustment of the material number lengths.
Migration via SAP S/4HANA Finance
The migration to SAP S/4HANA can also be performed with an interim step for SAP S/4HANA Finance. The logistical processes have not yet been simplified in this step. In technical terms, this is an add-on that is available as an add-on for enhancement package 7 for version 1503, or an add-on for enhancement package 8 for version 1605. Again, the migration is possible in one step, and the system must be a Unicode system. SAP provides customers with an ABAP report to check the requirements for this type of migration. This report must be run in the local SAP ERP system.