SAP S/4HANA Migration: Strategies and Challenges

SAP S/4HANA is the future of the SAP world – and companies that continue to rely on SAP will have no choice but to migrate their systems. The reasons for this lie not only in the expiry of maintenance for existing applications, but also in the technological and strategic necessity of keeping pace with the next generation of SAP.

The end of support for SAP ERP: deadlines and consequences

Many organizations still operate an SAP ECC system today – often stable, but technologically at its limits. SAP has clearly communicated the end of maintenance: regular support will end by the end of 2027, after which only paid extended maintenance will be available until 2030. Those who continue to rely on outdated software risk not only higher costs but also tangible disadvantages.

Outdated ERP systems such as SAP ECC entail some risks: security gaps, lack of updates, limited innovation capacity, and lack of compliance. The migration process to SAP S/4HANA is therefore not just an IT project, but a decisive step for the future viability of the entire organization. Early action is not only recommended here—it is essential to avoid pressure to act later and to ensure that the realignment is carried out in a controlled manner.

The advantages of S/4HANA: More than just an upgrade

Those who switch to SAP S/4HANA not only save time in terms of maintenance, but also gain a strategic advantage. This is because the platform brings with it numerous technological innovations that go far beyond what would be achievable with a classic upgrade.

At its core is the SAP HANA in-memory database, which enables high-performance real-time data processing. Analyses that used to take minutes are now available in fractions of a second. Added to this is the simplified data model, which streamlines processes and eliminates redundant tables. The modern SAP Fiori user interface also improves the user experience and reduces training costs.

S/4HANA also integrates future technologies such as machine learning, artificial intelligence, and process automation. The result is an ERP system that not only reacts but also proactively provides recommendations for action. This innovation makes all the difference in an increasingly data-driven world.

The switch to SAP S/4HANA offers numerous opportunities, but also presents challenges that should not be underestimated. These relate to both technical implementation and organizational preparation. Organizations should therefore address potential stumbling blocks at an early stage and develop appropriate strategies to minimize risk.

Technical hurdles: From custom code to data cleansing

One of the biggest technical challenges is adapting individual code that has accumulated in the system over the years. Many SAP customers have implemented extensive enhancements and modifications in their SAP ECC systems – either to map specific business processes or due to historically grown requirements. When switching to SAP, these developments must be reviewed, adapted, or even replaced. SAP offers tools such as the SAP Custom Code Migration Work list tool to identify incompatible code at an early stage.

Data quality is also a key issue. Inconsistent, duplicate, or incomplete data sets can cause massive problems in the new system. Thorough data preparation before the actual system changeover is therefore essential. This applies in particular to master data (e.g., customers, materials) and transaction data. Tools such as the SAP Migration Cockpit or SAP Data Services help to analyse, clean up, and migrate data in a targeted manner.

From a technical perspective, the situation is further complicated by the fact that S/4HANA introduces new table structures (e.g., ACDOCA) and technologies such as CDS views. These require an in-depth understanding of the new system architecture and careful planning—especially when integrating on-premise-based third-party systems.

Organizational changes: Change management is crucial

In addition to technology, it is above all the human factor that makes the difference between the success and failure of a migration project. An SAP S/4HANA implementation not only changes the IT structure, but also processes, roles, and workflows within the company. Without targeted change management, there is a risk of overload and resistance within the team.

Many employees have become accustomed to familiar transactions and interfaces over the years – switching to SAP Fiori can initially feel like a break with the past. This makes it all the more important to have a comprehensive qualification strategy that includes training, hands-on training, and ongoing support. Process owners in particular should be involved at an early stage. Only when they understand the potential of the new platform can be existing processes be optimized in advance – rather than simply being adopted “1:1.”

In complex organizations in particular, it is advisable to establish targeted communication measures to reduce fears, create openness, and promote engagement. Change management thus becomes an integral part of the entire SAP implementation.

A successful system conversion to SAP S/4HANA is based on a clear project structure. The following section provides a practical overview of the three central project phases – from preparation and implementation to stabilization after go-live.

Phase 1: Analysis and preparation

Every successful project begins with a thorough assessment of the current situation. This includes analysing the existing system landscape, the modules used, individual developments, and relevant processes. It is also necessary to examine the existing data quality and possible dependencies on third-party systems. The goal of this phase is to clearly define the business requirements and choose the appropriate migration path – e.g., Greenfield, Brownfield, or Bluefield.

The insights and training content from the hypercare phase should be secured for the long term. This can be achieved through documented training plans, e-learning offerings, and recurring qualification formats. In this way, knowledge is not only built up, but also retained and passed on within the company.

In S/4HANA projects in particular, it is crucial to consider training measures at a very early stage – ideally as early as the blueprint phase. This is because enabling project teams and key users is not only essential for the subsequent transfer of knowledge, but also for the success of the project itself: They are often not yet named or involved in the early stages of the project, even though their expertise plays a central role. Projects in which customers and internal employees are trained at an early stage significantly reduce their dependence on external consulting firms. Experience shows that this leads to more sustainable results because companies build up their knowledge in a targeted manner, thereby strengthening internal competencies. A good project therefore recognizes early on that training and enablement are strategic success factors – and integrates them consistently from the outset.

SAP supports this phase with the SAP Readiness Check, which provides a detailed technical analysis. This is supplemented by tools such as the Migration Object Modeler or the SAP Activate Framework, which provides a structured project approach in the form of phases, tasks, tools, and best practices.

Phase 2: Technical implementation

This phase involves the actual platform change. The SAP Migration Cockpit plays a central role here, enabling data-driven transfer of master and transaction data as well as configurations. The process is supported by predefined templates that accelerate standardized data transfer. For particularly complex scenarios, combination with SAP Data Services is recommended.

Test runs and fallback strategies are also important in this phase. This is the only way to ensure that the data has been transferred correctly and that the new system is functioning reliably. The integration of cloud components or third-party applications must also be carefully planned, especially in hybrid scenarios.

Parallel to the technical implementation, users must also be trained and the authorization concept adapted. Roles, access rights, and approval structures should correspond to the new processes in the SAP system – they should not simply be transferred.

Key tools for data migration

Successful data transfer is one of the most important steps in the implementation of SAP S/4HANA – it is a decisive factor in the success of the project. At the heart of this process is a central SAP tool that was developed specifically for transferring master and transaction data from an existing system to the new SAP ERP system. It replaces older methods such as LSMW (Legacy System Migration Workbench) and is tailored to the requirements of modern SAP landscapes.

The tool is based on predefined templates that map frequently used data objects such as customer master data, materials, vendors, or accounting documents. These templates can be used directly or customized. The Migration Object Modeler is particularly helpful here, as it can be used to model and extend new migration objects – a must for anyone working with company-specific data structures.

A major advantage is its close integration with the S/4HANA architecture: The SAP tool supports both on-premise and cloud scenarios, offers validation rules for data quality, and ensures that all steps are traceable through clear monitoring. It is an indispensable tool, especially in brownfield projects where a lot of legacy data has to be transferred.

The tool also provides valuable services for selective platform changes as part of a hybrid approach: It allows only certain modules or business units to be transferred to the new system – an advantage for companies with complex IT landscapes or multiple subsidiaries.

The tool set is rounded off by the option of connecting external data sources via SAP Data Services. This allows information from legacy systems, Excel files, or third-party systems to be consolidated and standardized – an important step toward transparency and data harmonization.

In short, those who have a close look at the central SAP tool for data migration are laying the foundation for a smooth, traceable, and secure transformation. It is much more than a technical aid—it is the operational core for the transition to the new SAP system.

Phase 3: Go-live and optimization

The go-live is undoubtedly the critical moment in any migration project. A well-prepared cut-over strategy, clear responsibilities, and a well-thought-out schedule are crucial. During the go-live itself, support from a dedicated hypercare team is necessary to respond immediately to disruptions or unexpected user behaviour.

But the project does not end with the go-live. Rather, this is when the phase of continuous improvement begins. SAP Analytics, KPIs, and feedback loops help to identify optimization potential at an early stage and further develop the system during ongoing operations. In many organizations, new functions are added at this stage – for example, for process automation, artificial intelligence, or mobile applications.

Many SAP S/4HANA migration projects do not go as planned – it is not uncommon for budgets and timeframes to be exceeded. But what distinguishes successful projects from failed ones? In this section, we show you which factors really matter and provide specific recommendations for a structured and successful implementation.

Why many projects fail – and how you can do better

According to studies such as the one conducted by Celonis, around 50% of all migration projects fail because they either exceed the planned budget or do not meet the set time targets. There are many reasons for this: inadequate planning, a lack of defined goals, overlooked technical dependencies, or poor communication within the project team.

A key success factor is a consistent view of the process: organizations that critically examine their existing processes before the system changeover not only identify potential for optimization – they also lay the foundation for more efficient implementation in the new system. So the motto should not be “copy old into new,” but rather “create new where it makes sense.” A clear process definition in advance is essential, as is clear prioritization: What must be ready for go-live, and what can be done later?

Programs such as the SAP Migration Cockpit help to reduce the technical complexity of data transfer. Combined with realistic milestones and a well-developed project plan, the risk can be significantly minimized. Working with pilot systems, test migrations, and reviews has also proven to be a pragmatic method of quality control. The consistent use of best practices is crucial here, as is the willingness to bring in external expertise when needed.

The role of partners and training

An SAP S/4HANA migration is a complex project that requires a wide range of skills, both technical and functional. Many organizations therefore choose to select the right partners to support them during critical phases. Consulting firms with experience in large S/4HANA projects can not only provide methodological support, but also help with risk assessment, custom code management, and the integration of cloud components.

But the right expertise must also be available internally: only when users understand the new system can its added value be fully exploited. That is why a comprehensive training concept should be part of every S/4HANA strategy. This involves not only traditional user training, but also teaching new ways of thinking about data, processes, and automation.

Some of the most important areas of qualification are:

• SAP Fiori: The new user interface requires a rethink in daily work.
• SAP HANA: Working with the in-memory database changes the way data is analyzed.
• SAP Activate: Those who are familiar with the official implementation framework can actively shape the course of the project.
• Migration Cockpit & Data Migration: Project teams need to understand the data migration tools in detail with the Migration Cockpit – from templates to the Migration Object Modeler.

With a strong internal team and targeted support from experienced SAP partners, a resilient project structure is created that can withstand even unexpected challenges.

SAP S/4HANA is not just a new ERP system—it is the technological foundation for future business models. Organizations that adopt the platform early on not only gain a modern system, but also lay the groundwork for digital innovation and sustainable growth.

SAP's roadmap: Cloud-first and intelligent ERP functions

SAP has a clear vision for S/4HANA: “Cloud First.” The focus is on flexibility and scalability, which are particularly crucial for global organizations. The RISE with SAP program supports this approach by offering a comprehensive all-in-one solution that combines software, infrastructure, and services. This enables companies to drive their transformation forward in a targeted manner – in the cloud, on-premise, or hybrid.

Technologically, SAP goes far beyond classic ERP functionality with S/4HANA. New technologies such as blockchain, IoT, and machine learning are deeply integrated. Real-time analytics, automatic anomaly detection, and data-driven decision-making processes are not a vision, but already common practice. The SAP HANA in-memory database is the key that makes all this possible.

SAP is also committed to continuous development: new releases with additional features and improvements are released several times a year. Those who migrate to the new platform early on not only benefit from innovations, but also avoid costly backlogs.

Act now: Your migration roadmap

The decision to migrate to a new SAP system should not be delayed. Although 2027 still seems a long way off, experience from many projects shows that a successful transformation takes time, planning, and resources. Acting now will not only give you a competitive edge, but also reduce long-term risks.

The next step should be a structured preliminary study: Which systems are affected? Which ERP systems should be transferred to the new architecture? What is the condition of the data? What expertise is available internally? This analysis forms the basis for a robust project approach.

It is also important to set the course internally: Who will be responsible for the project? What training courses need to be started? Is there potential for process simplification? Initial workshops with the specialist department or IT service providers can also help to flesh out the project and allay fears.

Those who approach the topic strategically, prepare in a structured manner, and invest early on will reap the benefits in the long term. Transparency, automation, flexibility—SAP S/4HANA heralds the next generation of SAP-based corporate management.