S/4HANA transformation: well planned from ECC to S/4HANA

Mainstream maintenance for SAP ECC ends on 31 December 2027 – for many large enterprises the moment to tackle the move to S/4HANA in earnest. We take on the steering of the programme on your behalf and work closely with the large international consulting firms that carry out the implementation.

In S/4HANA programmes we take on the steering of the project or individual sub-projects, advise on process and application questions and take on test, defect and cut-over management.

How you know you need this

It is rarely a single event that tips the balance. Usually several things come together:

Your ECC system runs on Enhancement Package 6, 7 or 8, and mainstream maintenance ends on 31 December 2027. Older releases have been without mainstream maintenance since the end of 2025.
You are facing a major investment in the existing system and are rightly asking whether it still pays off.
Your system landscape has grown over many years, and nobody can say with certainty any more which custom development is needed for what.
A group directive, a merger or a carve-out makes a common template necessary.

What the end of maintenance means in practice

After 31 December 2027 the standard contract for ECC 6.0 no longer includes security corrections or legal changes. Extended maintenance until the end of 2030 costs two percentage points more on the maintenance basis. It buys time but does not replace a decision. For RISE with SAP customers there is also a transition option for 2031 to 2033 at an additional fee – provided the system has been moved to SAP ERP, private edition on SAP HANA by the end of 2030.

Allowing 12 to 24 months for a corporate programme, the buffer until the end of 2027 has by now been used up. For most large enterprises the task is therefore to bridge the time until 2030 in an orderly way and to set up the transformation calmly in parallel. That is exactly where we support you.

First the route is decided

It starts with the question of the right path. Three variants have become established, and each has its merits:

Brownfield – system conversion

You take over your existing system including processes and data. This is the fastest route when your processes hold up and the deadline is pressing. You do, however, also bring along what has accumulated over the years.

Greenfield – new build

You build anew on the SAP standard. This is the most demanding route, but also the only one that truly cleans up. It pays off when the processes are due for a rework anyway or a group template is being created.

Selective Data Transition

You take over selected processes and data and deliberately leave the rest behind. For large landscapes where neither “take everything” nor “start from scratch” is realistic, this is often the right middle way.

Which variant suits you is something we clarify together using four questions: How sound are your current processes? How much custom development is in the system? How clean is your master data? And how much time do you have – until the end of 2027, until 2030 with extended maintenance or, through the paid transition option within RISE with SAP, until the end of 2033?

What an S/4HANA transformation adds

Before anything else comes the preliminary study: we assess your custom developments, check whether the system can be converted and work out with you the decision for brownfield, greenfield or Selective Data Transition.
The fit-to-standard workshops run per process area with your key users and each end in a firm decision: standard, extension or a deliberate no.
Testing here is a section of the programme plan in its own right, not an appendix to the build – alongside the integration test you need regression tests, because the conversion also touches processes nobody meant to change.
A dress rehearsal under real conditions comes before the cut-over. Only once it runs through inside the time window does the system go live.

The four steps that underlie every implementation project are described once on the SAP overview. How we work – the shared framework

For a corporate programme spanning several countries, 12 to 24 months is a realistic order of magnitude; for a single entity on the public cloud standard, more like 3 to 6 months.

From your side we need three people throughout: a project lead who can take decisions, one key user with functional responsibility per process area, and a contact for SAP Basis. And if decision paths on your side are not yet fully settled: that is no obstacle, but often the first point where we can support you.

What you end up with

A live S/4HANA system
A documented process map you can keep working with
Test and acceptance records across all process chains
A complete cut-over record
Trained key users who take ownership of their areas
A list of the topics deliberately deferred until after go-live

What we do not do

SAP Basis tasks such as installation, operation and system copies are not something we take on; they are in good hands with your IT or your hosting partner.
We do not develop our own code in SAP. Our focus is the SAP standard and its customizing. We are happy to review and assess customer-specific developments against the standard, but we do not build them ourselves.
The build of a corporate programme sits with the large international consultancies, which are set up for it. On your behalf we make sure decisions get taken and results fit your processes – the two tasks interlock, and that is exactly how we see the collaboration.

Typical questions

Can we simply extend beyond 2027?: Yes, extended maintenance runs until the end of 2030, on the terms set out above. It buys you time; the transformation itself does not get any shorter.
Do we have to move to the cloud?: No – S/4HANA can still run in your own data centre. If you want the cloud without giving up your own ABAP developments and the brownfield path from ECC, the Private Edition is the route for that. Bear in mind that SAP delivers new capabilities, especially around Business AI, to the cloud first. We are happy to assess separately with you which deployment model fits.
What happens to our custom developments?: They are assessed individually rather than adopted wholesale. In our experience, a considerable share of what sits in the legacy system has not been used for years. What remains we check against the standard; the implementation partner then carries out the changes.
Can we switch over during live operation?: Yes. The cut-over itself requires a weekend to a few days of downtime. Everything before it – build, migration tests, dress rehearsals – runs in parallel with your day-to-day business.
What goes wrong most often?: Data quality is tackled too late. Master data cleansing is seen as tedious groundwork and postponed until it becomes a schedule risk during testing. Pulling it into the preliminary study and defining mapping rules per field saves many times the effort later on.

Initial consultation on S/4HANA transformation

Feel free to describe your starting point – system release, timeline, landscape. Within two working days we will get back to you for an initial consultation of 30 to 45 minutes, free of charge. Consulting firms that want to hand over test or cut-over management as a work package are in the right place with the same message.