S/4HANA Transformation (3) – Details and tips

Cengiz Varol

Jan Hendrik Henke


In the first two articles, we addressed common challenges and outlined the appropriate project methodology for migrating from SAP ECC to S/4HANA. In this part, we aim to highlight a few specific features and offer some tips.

Major challenges

  • Complex legacy landscapes.
  • High levels of customisation.
  • Master data and its integration.
  • Data migration.
  • Choosing between Brownfield, Bluefield, or Greenfield.
  • Future infrastructure and cloud options, including hybrid models (e.g. Infrastructure as a Service, Software as a Service, Platform as a Service).
  • Time needed for transformation (especially for complex landscapes and the introduction of new functions and processes).
  • Change management (especially regarding the Greenfield approach, SAP FIORI, and new processes).

Minimum requirements

Although these don’t apply to every case, the following are technical prerequisites for conducting a migration:

  • Separating all dual ABAP & JAVA stacks.
  • Upgrading to ERP ECC 6.0 – EHP8.
  • Unicode conversion.

General issues and preliminary projects

Key issues that arise in the transformation process include:

  • Selecting the migration strategy
  • Operating models, possibly hybrid solutions
  • FIORI strategy
  • Preparatory projects (aside from the aforementioned minimum requirements)

Issue 1: Migration strategy

A migration or transformation presents not only new challenges but also significant potential, innovative approaches, and various opportunities. This scenario offers companies an excellent chance to consider a comprehensive redesign of their SAP model and to think about introducing a new data model. Indeed, poorly considered decisions in this regard can lead to substantial problems in the long run. Therefore, careful planning and analysis are essential to set the course for a successful future.

For a smooth and effective transition, the Brownfield approach is often the way to go, as it allows for a well-structured and organised process landscape. This method lets you optimise existing systems and processes while retaining what already works. In our project methodology, we offer an optional “Explore & Design Phase,” perfect if you aim to implement new functions and processes during a transformation process – from quick wins to major changes.

On the other hand, if your system is outdated or has accumulated many custom developments over the years, it might be wise to have a fresh start. The Greenfield approach gives you the chance to define and implement an entirely new process landscape. This way, you can move away from old structures and develop innovative, future-focused solutions. In this case, it’s a good idea to include the “Explore & Design Phase” in the project methodology or as a preliminary step. This phase evaluates new functions and processes using S/4HANA as well as the potential for innovation, including cloud solutions.

Issue 2: Operating models

SAP S/4HANA offers a variety of operating models tailored to fit different business processes and IT strategies. These models differ in how they configure software applications, platforms, and infrastructures to meet the unique needs of each company. The main options are:

  1. Public cloud: This solution is great for flexibility and low maintenance, as it’s fully managed by SAP. This allows for quick implementation and regular updates, making it ideal for companies looking for a cost-effective and scalable solution without worrying about technical maintenance (e.g. SAP GROWTH or SAP RISE Public Cloud Initiative).
  2. Private cloud: This offers a dedicated environment managed by SAP or a trusted third party, combining the benefits of cloud technology with increased control and customisation, making it suitable for organisations with specific security, compliance, and customisation requirements (e.g., SAP RISE Private Cloud Initiative).
  3. On-premise: This option lets companies install and manage SAP S/4HANA on their servers, providing the highest level of control and customisation. It’s especially suited for organisations with complex integration processes or those requiring full control over their data and systems for regulatory reasons.


When choosing the right operating model, companies need to consider several factors beyond just the technical aspects. These include internal company structures, long-term business strategies, and specific compliance requirements. This becomes particularly challenging with hybrid models, which are a popular choice as they allow you to gain initial experience with cloud solutions (e.g. SaaS, PaaS). However, these scenarios require you to pay extra attention to the integration strategy and its solutions.

Issue 3: FIORI strategy

  • Fiori only: This approach focuses exclusively on using SAP Fiori, making it perfect for companies looking to fully transition to the latest user interface technology. It provides a unified and modern user experience, ideal for organisations aiming to simplify and standardise their processes.


  • Hybrid solutions: This combines SAP Fiori with traditional SAP interfaces like SAP GUI. It’s a great option for companies preferring a gradual migration or having specific needs better met by existing interfaces. A hybrid approach allows for flexible migration and the ability to adjust specific functions and processes as needed.

Preparatory projects

To gain some initial experience and make the transformation smoother later on, it’s a good idea to start with these preliminary projects early on:

  • BP Conversion, i.e. Customer-Vendor Integration (CVI),
  • New General Ledge Accounting.
  • Removing, cleaning, or archiving old data.


The Readiness Check often highlights the need for “Deep-Dive Workshops.” While many results and recommendations from the check are straightforward, some aren’t. Therefore, it is often beneficial to explore the functionalities and processes in more detail to get a better estimate of the necessary activities, effort, and duration. These detailed workshops might also uncover the need to implement certain activities as part of a preliminary project.

Main project

While there are many topics to cover, here are a few key aspects summarised briefly. Switching to SAP S/4HANA requires a structured and thorough approach to ensure the migration is efficient and effective. This process can be broken down into four main steps:


  1. Reviewing with the Maintenance Planner: The first step is to check the compatibility of your existing business functions, industry solutions, and add-ons with SAP S/4HANA. The Maintenance Planner is an essential tool to help determine which components are suitable for the transformation and identify any necessary adjustments or upgrades.
  2. Using the Simplification List for analysis: The second step involves using the Simplification List to understand how your current transactions and functions will change with SAP S/4HANA. This list provides detailed information about the changes in the new system environment and helps in realistically assessing the migration effort.
  3. Conducting pre-checks: The third step involves running specific pre-checks to review the current SAP system settings, making sure all necessary prerequisites for the system conversion are in place. This critical phase confirms that the system environment is ready for migration.
  4. Custom Code Compatibility Check: The fourth, yet equally important, step is to check the compatibility of custom code with SAP S/4HANA. This involves a thorough analysis of existing custom code to ensure it works correctly in the new system environment, possibly requiring adjustments or optimisations.


In addition to these steps, it’s wise to develop a comprehensive data migration and management strategy. This should include planning for data transfer, ensuring data integrity, and having contingency plans ready for any complications during the migration.

Sandbox Testing

From our experience, it is highly recommended to use a sandbox environment for initial tests:

  • Create a sandbox as a copy of the production system.
  • Perform a test migration in the sandbox following a detailed plan, such as by:
    • Running migration cycles, including data transfer and system configurations.
    • Making corrections to master and transactional data in both the sandbox and production systems.
    • Exporting all transports from the first sandbox system.
    • Creating a new copy of the production system (second sandbox system).
    • Repeating the test migration and importing the transports from the first sandbox system.
  • The aims are:
    • Minimising downtime for development and test systems.
    • Conducting comprehensive tests to make sure all processes work correctly.
    • Only after the above transitioning the development system to S/4HANA, followed by the Q and P systems.


As companies move forward with migrating from SAP ECC to S/4HANA, it’s important to conduct detailed analyses and plan thoroughly to select the right strategy, meet minimum requirements, and address essential issues. This involves considering both technical aspects and specific business needs. Preliminary projects can thus help by streamlining the transformation process and providing valuable initial experience.


Interested in learning more about S/4HANA Transformation? Get in touch with us to find out more.