All support for SAP’s ERP Central Component (ECC) is expected to expire by 2025, necessitating that companies running SAP to move to the new S/4HANA system before 2025. This means migrating data from the current SAP legacy SAP system to S/4HANA. Although a plethora of benefits has prompted the move to S/4HANA, it comes with many challenges specific to migrating data from the source system to S/4HANA. The following insights and information can help with the process of migrating legacy data from a non-SAP or SAP ECC legacy system(s) to a S/4HANA 1709 on-premise version.
Examples of variables in data migration
When data is being migrated from one system to another, there are always hurdles to overcome. The level of difficulty depends on the answers to these questions and more:
- What data is being migrated?
- Where the data is sourced from?
- What is the volume of data being migrated to the target system?
Anytime S/4HANA is the target system, migration challenges are magnified in cases where data structures have been modified from the traditional SAP ECC systems.
Pitfalls associated with migrating data to S/4HANA
Snags have been reported by companies migrating legacy data to S/4HANA, leading to multiple unplanned hours addressing each problem. More than one-third of companies surveyed regarding the migration of legacy data to S/4HANA reported that a lack of skills and knowledge was one of the most significant problems. Other challenges include:
- Heavy customization in source systems
- Complex legacy landscapes
- Lack of data cleansing
- Non-harmonized master data
When companies have made major investments in custom ABAP developments, what often happens is that much of their legacy code is incompatible with the new S/4HANA system. Some custom tables have to be replicated in S/4HANA or redefined to keep the existing functionality. The best way to prevent unexpected results from syntax errors and other errors to identify the custom ABAP code objects and modify them to be compatible with S/4HANA.
Complex legacy landscapes
Homegrown legacy systems typically include complex landscapes that complicate migration to a new system. It is important that these issues are all addressed while preparing for migration. Multiple SAP systems and non-SAP systems are part of legacy landscapes that encompasses several custom modules, bolt-on developments, configurations specific to a country, and interface dependencies.
Lack of master data cleansing
Master data plays a crucial role spanning many aspects of a business, such as supply chain management, sales, marketing, manufacturing, logistics, finance, etc. It is vital to have data cleansed well before conversion to S/4HANA. If unclean data is used during conversion, obstacles can be expected.
The three critical aspects of clean data are consistency, completeness, and content accuracy.
Non-harmonized master data
Data harmonization is a relatively new yet indispensable process that puts data to work for companies on a whole new level. It brings various file formats, columns, and naming conventions together and transforms them into a cohesive data set. Also known as “data normalization,” it means that the underlying features of your data are the same.
Challenges with specific migration tools
Different tools can be used for the migration of legacy data to S/4HANA. Options include Data Migration Cockpit (DMC), Legacy System Migration Workbench (LSMW), SAP standard transactions, and the development of a new program for migration purposes. Below are a few insights from experts on challenges associated with the use of LSMW and DMC for migration to S/4HANA:
Although LSMW is available in the S/4HANA environment, SAP recommends that it not be used for data migrations. The primary reason for this is that LSMW uses standard interfaces like BAPI, IDOCs, Direct Input and Batch Input programs and recordings. There are restrictions for the use of these programs in S/4HANA, hence SAP’s recommendation not to use LSMW for data migrations. If the project team still wants to use LSMW, thorough testing is required to ensure it works in specific cases.
DMC can be used and is recommended by SAP as a migration tool, but it has its own set of challenges. For example, DMC has limitations on the number of data objects that can be transferred. The following are examples of issues experts had to sort out on various projects:
- If the number of warning messages exceeds a certain limit (like 1000), then data gets missed out in DMC after the file is uploaded. Also, data gets muddled, such as gross weight, net weight, weight UOM, etc.
- DMC cannot handle a huge volume of data.
- If the load file from the key users does not come exactly as DMC expected, it will show error messages and no additional columns can be added. If an additional field is necessary, it should be mapped first in modeler and then it can be added to the template file.
- An example related to migrating production ‘routing’ data – if an “operation” is relevant for costing, map such value in the uploading template because this is not a standard field in DMC.
- Some fields that manage decimals might return an error message because in decimals it is required to clean out additional positions to avoid this message.
Why choose SAP S/4HANA?
Many companies have been deciding to do more than simply migrate legacy data, as the situation demands. They are choosing the S/4HANA system because of distinct benefits the system offers, which represent a substantial upgrade. It is a synergistic digital core that allows you to unify enterprise-wide processes and modernize your system architecture.
Due to complexities associated with the migration of legacy data to S/4HANA, help from experienced experts is the best way to avoid undesirable outcomes.
Not sure where to start? Our SAP consultants are knowledgeable about S/4HANA migration challenges and will be able to work with you in deciding what approach (brownfield, greenfield or a combination of both) makes sense for your business.