With SAP ECC mainstream maintenance ending on 31 December 2027, most South African organisations now have an S/4HANA migration on the agenda. The first question is usually “which edition and when?” The better first question is “what are we actually moving?”
The problem nobody has a full picture of
After years of projects, most ECC systems carry a large amount of custom code: reports, enhancements, interfaces and modifications to SAP standard. Much of it is still needed. Some of it is obsolete. Some of it blocks S/4HANA. The trouble is that nobody can say which is which, and that uncertainty makes every migration estimate look riskier than it should.
What a clean core means in practice
A clean core is an SAP system kept close to standard, with extensions built through released interfaces or on the platform instead of inside the core. The payoff is practical: upgrades stay predictable, and you can adopt new SAP capabilities, including SAP Business AI, without a remediation project first.
Start with an inventory, not a budget
A structured clean core assessment gives you the baseline a migration plan needs. It looks at your landscape across five areas: processes, extensions, data, integration and operations. For the custom code, it answers four questions about every object:
- Is it used? Usage data shows what runs and what has not been touched in years.
- Can it be retired? Unused objects should not travel with you.
- Can it be adapted? Some code only needs changes to fit S/4HANA.
- Should it move to the platform? Some extensions belong on SAP BTP, outside the core.
The result is a prioritised roadmap you can size and budget, with quick wins first.
Do it before you migrate, not after
Cleaning up before the move is cheaper than carrying everything across and cleaning up afterwards. It also shortens the project, because you only convert and test what earns its place. And you do not need to be on S/4HANA to start: an assessment on ECC is the best input for sizing the migration.
Keep it clean afterwards
A clean core only stays clean with rules everyone follows. That means development standards, a simple guide for choosing between key-user, on-stack and side-by-side extensions, quality checks in the transport process, and a light design authority for new developments.
If you want to know where your landscape stands before you commit to a migration budget, read how our clean core assessment works or talk to one of our consultants.
