- System Conversion
- New Implementation
- Selective Data Transition
If you are new to the topic, read my other blog first on moving to SAP S/4HANA. This provides some background and detail on the other two approaches. https://blogs.sap.com/2019/10/30/how-to-move-to-sap-s4hana/
Selective Data Transition is an alternative to the New Implementation approach (also called greenfield) or System Conversion approach (also called brownfield). It is relevant for customers moving from an existing SAP ERP solution to SAP S/4HANA on-premise or SAP S/4HANA Cloud extended edition. For details on S/4HANA deployment options, see my blog: https://blogs.sap.com/2019/08/22/sap-s4hana-cloud-and-on-premise-deployment-options/#
As its name implies, this approach involves transferring data from one or more existing ERP solutions to a new S/4HANA solution. The transfer is done by SAP or partners that provide specialized tools and services. The data selectively transferred can include:
- ABAP repository of objects and developments
- Configuration (customizing) data
- Master data
- Transaction data (historical closed items and open items)
There are two common approaches to create a target system with Selective Data Transition: Shell Conversion and Mix and Match. In Shell Conversion, a shell copy of a production system is made without master and transaction data and this is converted to SAP S/4HANA. In Mix and Match, a new S/4HANA install is created and then elements of the existing configuration and ABAP repository are transported or manually transferred. Both scenarios require data migration to follow including master data, balances and open items. A comparison of the approaches is shown below.
The data is moved using SAP Data Management and Landscape Transformation (DMLT) software and related services. For over 10 years, SAP DMLT have provided well established solutions for organizational changes, acquisitions, divestitures, or harmonization of SAP landscapes. The software provides highly automated processes that move large amounts of data between SAP instances quickly. Similar software and services are provided by third party vendors for S/4HANA on-premise. More detail on these later. For S/4HANA Cloud extended edition, SAP DMLT must be used.
Selective Data Transition should be considered when organizations need to:
- Go live in phases (e.g. by country or business unit)
- Reduce risk of a big bang go live
- Split or merge existing SAP ERP instances
- Leave behind large amounts of old data e.g. to reduce the duration of system conversions and cutovers
- Reduce re-implementation effort by re-using elements of the solution whilst redesigning others
The split and consolidation of ERP instances is a large topic in its own right and is not covered in detail here. Instead, I focus on how Selective Data Transition can be used to phase go-lives. This may be required in ERP solutions with large data volumes or with many users in multiple countries.
As stated earlier, the starting point is to create a parallel S/4HANA sandbox or development system. A new clean install of SAP S/4HANA can be used (Mix and Match approach). Alternatively, use SAP DMLT to create a “shell” copy of an existing ERP system (Shell Conversion). The shell contains the ABAP repository and configuration data without master data or transaction data. A system conversion is done to turn this into an S/4HANA instance. The conversion process is simpler and faster without the master and transaction data and certain S/4HANA Simplification Items can be more easily implemented without business data.
For selective data migration of master and transaction data, SAP DMLT tools are used. If no historical transactions are required and only open transaction items are needed, the S/4HANA Migration Cockpit (direct transfer scenario) may be simpler. SAP DMLT allows a time slice of historical transaction data to be migrated.
An example project scenario using Shell Conversion is described below. This assumes a two stage project. The first stage is a technical transition followed by a second stage to implement business transformation innovations. The first technical transition stage is outlined below:
- Engage SAP DMLT or a partner to advise on the approach. This may lead to preparation work in the existing ERP system.
- Analyze DMLT source system functionality e.g. using Business Process Improvement within Solution Manager.
- Analyze existing landscape using SAP Readiness Check and SAP Business Scenario Recommendations (BSR).
- Execute S/4HANA preparation activities in the existing ERP solution e.g. archive data to reduce data footprint and remove unwanted custom code and configuration. Also perform Customer Vendor Integration (CVI) to make business partner the lead object.
- Create a new S/4HANA sandbox system. Create a shell copy using a recent copy of a production ERP instance
- Perform an S/4HANA system conversion of the shell system.
- Make configuration changes required to execute Fit-Gap workshops.
- Conduct Fit-Gap / Delta Design focusing on mandatory S/4HANA Simplification Items.
- Set up data migration tools and environment.
- Create a new S/4HANA development system using a shell copy of the sandbox system.
- Set up a production support track for on-going maintenance of the live solution.
- Make configuration changes required for Simplification Items.
- Adapt ABAP code for S/4HANA
- Implement any changes required for integration and analytics solutions.
- Execute multiple data migration test cycles using DMLT in the sandbox.
- Set up a quality assurance system and production system with a copy of the S/4HANA development shell without master and transaction data.
- Test selective migration of master and transaction data in the Quality Assurance system.
- Set up SAP Information Lifecycle Management (ILM) and a retention warehouse to move old data onto a low-cost infrastructure.
- Run integration and User Acceptance tests.
- Rehearse the cutover.
- Migrate master data and, if required, historical transaction data into the Production system.
- Cutover to the production. Migrate open transaction item data and master data that has changed since the last migration cycle.
Once the technical transition stage is complete, a second project stage can be kicked off to implement business transformation innovations e.g. to adopt SAP Fiori apps. The first stage is led by a technical team and the second stage is led by the business.
This approach may be flexed. For example:
- First go-live could include business transformation scope in addition to the technical conversion.
- S/4HANA preparation activities in the prepare phase could be done in the sandbox rather than the existing ERP solution.
- During the technical transition, configuration and ABAP code adaption could be done in the sandbox system and then moved to the development system. This can reduce the duration of the production support track.
- Multiple sequential go-lives could occur with master and transaction data migrated as required e.g. by country and company code.
- Selectively transfer business and master data from multiple source ERP systems. A pre-requisite for working with multiple source systems, is that the ABAP repository and configuration of the source systems are compatible. Harmonization work is required in the Prepare phase.
- Only use the S/4HANA Migration Cockpit for data migration (excluding historic transactions). This provides a more application focused approach when compared to the technical migration involved in DMLT services. Less harmonization work may be required.
- The old production system may be de-commissioned to a dormant status to access historic data and archived data.
There are four partners that provide software, tools and services for selective data transition:
These are alternatives to using SAP DMLT for SAP S/4HANA on-premise projects. These organizations are part of a global expert community. You can get more details of their offerings at these links:
I hope you found this blog informative.
Enterprise Architect at SAP Digital Business Services UK