Why SAP ECC Phaseout 2027 is a Critical Milestone

The announcement that SAP will end mainstream support for ECC (ERP Central Component) on December 31, 2027 represents a turning point in the IT landscape for many mid-sized companies. We see clear pressure to act here, because anyone continuing to rely on SAP ECC after this deadline must reckon with rising maintenance costs. Some sources speak of around 2 percent annual fee increases if no switch to S/4HANA takes place [1]. Even more serious: with the end of support, important security updates and official product innovations end. This not only increases security risk but can also slow down the further development of business processes.

In our experience, early planning is crucial in order to avoid cost explosions, skills bottlenecks, and operational risks. Migration takes 18 to 36 months depending on complexity, which according to surveys is a typical period budgeted for the switch to S/4HANA [2]. Especially with a view to 2027, every month is therefore valuable. Our observation in the mid-market shows that acting too late often leads to rushed IT projects that are not only expensive but also risky.

It is also interesting that to date only around 39 percent of ECC customers have purchased an S/4HANA license (as of the end of 2024) [2]. This means that very many organizations still face the same problem. We are convinced that the situation will become even tighter in the next two years when everyone tries to modernize the SAP ecosystem at the same time. Anyone driving the switch now not only secures competitive advantages but also avoids bottlenecks in consultant and developer capacity.

The Most Common Challenges in Migration

Replacing SAP ECC with S/4HANA is not just a technical upgrade but typically a comprehensive digitalization project. Common challenges we encounter in practice include:

• Ensuring data quality and consistency in fragmented systems
• Mapping individual customizations (extensions, in-house developments) in the new system
• Legal and regulatory requirements, especially with regard to data protection and compliance
• Cultural change in the company, especially when new processes have to be introduced or old workflows abandoned

In many companies, there is also pronounced heterogeneity in the IT landscape. We often see older legacy systems alongside modernized cloud solutions, which complicates integration. Anyone not planning carefully here risks isolated solutions with redundant data or double maintenance effort. In addition, the innovations in S/4HANA, such as the use of the in-memory database SAP HANA, place partly completely different demands on infrastructure and competencies.

A fundamental stumbling block is internal coordination: large transformation projects need unified goals and clear responsibilities. If management backing or interfaces between IT, business units, and finance officers are missing, the project stalls. We therefore recommend bringing central stakeholders together even before project start. Misunderstandings can thus be clarified and overarching goals defined that are supported by all areas.

Support Through Funding Programs

In the mid-market, we often see that the financial and organizational efforts in the course of an SAP migration are underestimated. Yet various funding programs exist in Germany, such as KfW funding, that can support digitalization initiatives. We have noticed that many decision-makers do not know the conditions or funding paths precisely. We have therefore compiled some tips in our article KfW funding for digitalization on how to identify and apply for suitable programs.

In addition, you should examine whether industry- or region-specific funding opportunities exist. Some federal states grant subsidies for digitalization projects or provide low-interest loans when a comprehensive modernization concept is presented. These instruments can mean not only financial relief but also make investment in advanced technologies more attractive. Especially in longer-term transformation projects such as the SAP ECC phaseout 2027, a combined financing concept can be sensible to keep the budget stable.

We advise including the application for a funding loan or grant in migration planning from the outset. Funding bodies often require a precise description of project goals and timelines. Anyone compiling this information late risks loss of time or rejection of the funding application. With a clear roadmap, the chances of positive approval are greater.

Possible Migration Paths to S/4HANA

SAP offers various approaches for switching from ECC to S/4HANA. In practice, these approaches are known by the names Greenfield, Brownfield, and Hybrid [3]. From our perspective, no universally best solution exists. Each option has its own advantages and disadvantages that depend on factors such as project budget, time frame, and individual system history.

Greenfield

A Greenfield approach means setting up S/4HANA on a green field, so to speak. We recommend this approach for companies that want to fundamentally overhaul their processes or whose ECC system is heavily fragmented. Greenfield delivers a modern, clean system landscape and requires no takeover of legacy assets. However, the initial implementation is often laborious, since all configurations, processes, and data must be redefined.

Brownfield

In the Brownfield approach, companies convert their existing ECC system directly into S/4HANA. The old system logic remains largely intact, which can lead to a faster go-live. For reasons of economy, Brownfield is suitable above all when existing processes are already well established. However, the transfer of legacy data, in-house developments, and customer modifications can be complex and partially diminish the advantages of the new platform.

Hybrid

The Hybrid approach combines the advantages of both worlds. Here we change only certain parts of the system fundamentally (Greenfield) and convert other areas (Brownfield). This can be sensible when individual modules run very well and others have to be completely overhauled. However, this increases the complexity of the project, since a mix of methods is used. For large mid-sized companies, however, Hybrid can enable a time-managed, risk-reduced implementation by migrating critical areas in stages.

Below is a brief overview:

| Migration Path | Advantages | Disadvantages | | --- | --- | --- | | Greenfield | Fresh build, clean processes, no baggage | Highest initial effort, cultural change required | | Brownfield | Faster conversion, leverages existing processes | Legacy data and developments are carried along | | Hybrid | Flexible, only what is necessary is rebuilt | Complex coordination, parallel operation possible |

License and Cost Aspects

With the SAP ECC phaseout in 2027, a new arrangement of license models arises. SAP introduces partly different metrics for S/4HANA, for example the Full Use Equivalent (FUE) for users and document counting via Digital Access [2]. We consider it particularly important to examine these new conditions in order to avoid license overhangs or hidden costs.

It should also be noted that taking advantage of Extended Maintenance until 2030 is possible but comes with additional fees [3]. For us, this is more of a transitional option that only makes sense if a short-term migration is not realistic. The long-term approach should always be: invest in a modern landscape as soon as possible rather than accepting maintenance costs for a discontinued model.

On the other hand, there are companies that decide to switch to third-party support providers such as Rimini Street or Spinnaker Support [4]. This can lower maintenance costs but comes with the disadvantage of decoupling from SAP's official supply of updates and innovations. From our perspective, this only makes sense in exceptional cases, for example when a company is in a transitional phase or is about to radically change its business models.

Anyone who wants to create a meaningful cost overview must consider not only software licenses but also project effort, hardware/cloud costs, and the training effort for employees. Implementation and operating costs often far exceed pure license costs. We recommend setting up a budget very early that includes all project phases. Our experience shows that through precise coordination with finance officers and use of state funding, you can in many cases ensure a viable overall framework. You will find more on this in our article IT modernization ROI.

Risks of Delays and How to Avoid Them

Anyone who tackles the SAP ECC phaseout 2027 too late risks several problem areas at once. First, there is the risk of not finishing the changeover in time and thus having to pay more expensive support fees. Possible capacity bottlenecks at consultants, developers, and service providers come on top. Since the SAP ecosystem will likely experience boom conditions on the topic of ECC phaseout from 2025, fees for external help are likely to rise.

A further risk concerns the continuity of business processes. If important security updates are missing or compatibility problems with modern applications occur, system outages or data loss can occur in the worst case. We also often see in the mid-market the danger of missing personnel resources, since the IT department is often already busy with day-to-day operations. If a major migration project is added, this quickly leads to overload without supplementary external support.

From experience, we recommend dividing the project into sub-projects step by step: for example, you can start with the financial modules, then integrate logistics, and finally adapt reporting. This distributes the risk and the systems continue to run largely stably. In addition, an early-prepared training concept helps employees internalize new processes more quickly. According to our experience, in-house training accompanied by key users from the business units is a good way to gain as much acceptance as possible.

Data Management and Compliance

With the phaseout of ECC, the question also arises of how to correctly migrate historicized data and archive holdings. This concerns not only the IT side but also legal aspects. We like to point here to the GDPR and similarly strict compliance regulations that govern the handling of personal data. Anyone acting carelessly here risks substantial fines. Tips for handling older systems and GDPR compliance are compiled in our article GDPR and legacy systems.

The keyword "Compatibility Mode" also comes into play here. Originally, this — which allows classic ECC functionalities to continue to be used in S/4HANA on-premises — was supposed to expire at the end of 2025. It has now been extended until May 2026 [1]. Even so, this is only a limited grace period. Anyone modernizing their data architecture much too late risks having to lift both technical and data protection adjustments at once afterward. For us, it is clear that an orderly transition is significantly less risky than a postponed major project.

In addition, legacy data in many cases must be cleaned, encrypted, or deleted to meet current standards. We therefore always recommend a thorough data cleanse before or during the migration. Minimizing data volume can shorten project duration and save costs in the long term. Savings of 30 to 70 percent in data volumes are often possible when correctly archiving and transferring only relevant data records into the new landscape [3].

Best Practices for Successful Project Planning

For us, it is clear: a successful SAP ECC phaseout 2027 begins with careful project planning that is divided into four core phases.

1. Project initialization In this phase, together with all stakeholders, we define the goals, scope, and budget. Executive-level sponsorship is at least as important as the involvement of the affected business units.

2. Fit-gap analysis To understand which functions from the old system should be carried over into the new one, a fit-gap analysis is indispensable. Here we evaluate which core processes need to be set up anew and what can be carried over without problems. According to SAPinsider, this analysis is decisive for reducing downtime after migration [5].

3. Implementation and testing Depending on the chosen migration path (Greenfield, Brownfield, Hybrid), the technical implementation now takes place. Test runs are conducted in parallel. It often becomes clear here how thorough you were in the planning phase. We recommend testing particularly critical modules such as financial accounting or production control intensively before going into productive operation.

4. Go-live and stabilization After go-live, the phase of fine-tuning starts. User feedback, process optimization, and performance monitoring have top priority here. It is important to continuously provide training and support so that the workforce can quickly find their way around in the new environment.

Through this structured approach, risks can be minimized and both technical and organizational complexity managed. Companies that have clearly defined milestones and responsibilities at each step achieve in our experience noticeably higher success rates. We also recommend always seeing the modernization of legacy applications in the context of a larger digitalization strategy, for instance in the sense of modernizing legacy systems in mid-market companies.

To round off, we want to emphasize that these best practices are not a rigid blueprint. Every company has its own structures, processes, and requirements. The important thing is to plan enough time for analysis and testing. Because anyone who stumbles into a migration without clarifying the basics often pays the price later in the form of project delays and double work.

Conclusion

The time until the SAP ECC phaseout in 2027 may seem long at first glance, but in IT project terms it is extremely tight. We are convinced that only proactive planning and a systematic approach can unfold the full potential of a switch to S/4HANA. Companies that approach the process in a structured way benefit not only from current software and the comprehensive innovation potential of in-memory technology but also create the basis for long-term growth.

In addition to the technical aspects, it is essential to keep the economic perspective in view from project start. This means integrating funding options such as KfW programs, understanding the new license models, and realistically assessing internal resources. Compliance issues must also be clarified, especially when it comes to GDPR-compliant data use. Anyone acting proactively here can position their company more agilely and resiliently.

We see a future-oriented IT landscape as a key factor for staying competitive in the long term and using digital innovations. At the same time, you must not forget that such a migration is a cultural change. In our experience, this only works when management and workforce pull together. Then completely new doors open through the changeover in the sense of a true digital transformation. A carefully planned and successfully executed switch away from SAP ECC by 2027 is therefore more than a mere mandatory exercise. It is the foundation for sustainable innovation capability and efficient business processes in the mid-market.