But the question isn’t just when to migrate – it’s also how. SAP offers three distinct upgrade paths: Brownfield, Bluefield, and Greenfield, each with its own set of advantages and challenges. Whether looking for a fast, low-disruption conversion or a complete system overhaul, understanding these options is essential for making an informed decision.
In this article, we explore the latest deadlines, upgrade options, and strategic considerations to help navigate an S/4HANA migration with confidence.
SAP had announced in 2020 that they would provide mainstream maintenance for SAP Business Suite 7 core applications (which includes SAP ECC 6.0) until the end of 2027. However, for ECC 6.0 Enhancement Packages 0–5, mainstream maintenance ended on December 31, 2025, with no extended maintenance available. For ECC 6.0 Enhancement Packages 6–8, mainstream maintenance continues until December 31, 2027, with optional extended maintenance available until December 31, 2030 at an extra premium. So SAP ECC 6.0 (EHP 6–8) could continue to be used until 2030, but ECC 6.0 EHP 0–5 is no longer supported after December 31, 2025.
The new ERP solution of S/4HANA was released by SAP around 2015. S/4HANA uses an innovative database called HANA, which allows much faster online transaction processing (OLTP) and online analytics processing (OLAP). S/4HANA also features a simplified data structure, and new Fiori Apps are available, which are much more intuitive to use compared to the old SAP transactions. SAP has been providing innovative capabilities like predictive analytics, machine learning, and robotic process automation (RPA), and these innovations continue to evolve in line with technological changes.
For any customer that wishes to move to S/4HANA, there are three available options, illustrated below:
Option 1: System Conversion (Brownfield)
Involves upgrading or converting an existing SAP ERP system to an S/4HANA system.
This is also known as the Brownfield option and is applicable for companies that are on SAP ECC 6.0. It allows an in-place conversion of the existing system. Tools are available for System Conversion in a single step, and this is normally the fastest option to move to S/4HANA with the least downtime. Either the On-Premise S/4HANA or S/4HANA Private Cloud could be used as the target S/4HANA system in the case of a System Conversion.
This option is suitable for moving quickly to S/4HANA with minimal disruptions to the business, as the historical data and most configuration/set-up is retained. This also means that comparatively less training is needed for the business. Additionally, Fiori doesn’t need to be implemented at the same time as the S/4HANA conversion and could be implemented in a subsequent stage of implementation.
On the downside, as the historical set-up is retained in the new S/4HANA system, businesses might not be able to make use of the latest innovations that S/4HANA offers until further changes are planned subsequent to the system conversion to align the business closer to standard S/4HANA. An important point to keep in mind is that S/4HANA is different from ECC 6.0 in terms of the database and underlying data structure. So, if a company has a lot of bespoke functionalities, testing needs to be conducted very diligently, involving the business users to ensure that bespoke functionalities work as intended after the Go-Live.
In order to allow SAP ECC 6.0 customers to transition more smoothly into S/4HANA, SAP has also provided Compatibility Packs, which allow some of SAP ECC 6.0’s legacy functionalities (which SAP has considered non-strategic and are no longer available in S/4HANA) to continue to be used until May 31, 2026. After this date, customers will be expected to stop using the compatibility packs, as SAP may disable these functionalities in future updates.
Option 2: Selective Data Transition (Bluefield)
Allows organisations to selectively adopt some functionalities of the S/4HANA system while retaining the existing SAP ERP system.
Also known as the Bluefield implementation, this is a more controlled approach than a Brownfield implementation. In this approach, the whole business doesn’t move to S/4HANA in one go, or the ECC 6.0 system does not get converted to S/4HANA. Rather, selective S/4HANA functionalities are used, or selected modules are migrated to S/4HANA. So, the old ECC system is retained along with its functionalities and data, while some chosen business processes or modules would start to be used in S/4HANA, thus creating a hybrid environment. This allows for a more phased approach than a Brownfield implementation and hence greater flexibility in planning the move to S/4HANA. Either the On-Premise S/4HANA or S/4HANA Private Cloud could be used for S/4HANA functionalities in the case of a Selective Data Transition.
As the business doesn’t need to change all the processes in one go, there is slightly limited change impact. This enables businesses to leverage some chosen key functionalities available in S/4HANA while the remaining business continues to work in the old ECC system with a lesser change impact.
On the downside, businesses need to carefully choose which functionalities to use in S/4HANA and which functionalities to retain in the older ECC system. It is also an added complexity to have integration between the S/4HANA system and the older ERP system. Additionally, since S/4HANA is not fully implemented for the business, all the innovations available in S/4HANA will not be available to the business.
Option 3: New S/4HANA Implementation (Greenfield)
Involves implementing a fresh S/4HANA system independent of any existing system.
Also known as the Greenfield approach, this approach provides a fresh start for ERP processes, where the business normally looks at the existing business with a mindset to rethink, redesign, and optimise the business processes. This is a clean approach where the migration will not move the ineffective or inefficient data, enhancements, modifications, etc., to the new installation of S/4HANA. It is an opportunity to get rid of obsolete processes and bespoke functionalities, which might have been useful earlier when the existing ERP system was installed but are no longer relevant or might now be available as standard S/4HANA functionalities. A Greenfield approach is agnostic of the existing ERP system (or the lack thereof), as a new S/4HANA system is installed. Businesses could decide to go for S/4HANA Public Edition, S/4HANA Private Edition, or S/4HANA On-Premise (S/4HANA Public Edition has a comparatively limited set of functionalities available but might be suitable for smaller and medium enterprises).
As any existing ERP system (if applicable) is not impacted, it is possible to do a Greenfield S/4HANA implementation in phases, thereby having a higher level of flexibility in implementation. Businesses might also decide to do a pilot to understand the S/4HANA system and gauge its impact on the business, and the learnings could then be used while rolling out S/4HANA across the complete organisation.
If standard S/4HANA functionalities can be utilised as much as possible, this would reduce the testing effort during implementation, and any future system upgrades will be easier to manage.
With a fresh S/4HANA implementation, there are limitations to data migration, and only the relevant data is migrated to S/4HANA. Historical data is not available in the new S/4HANA system, though there are archiving options available separately to retain access to old data – something to keep in mind if access to old data is needed for legal or regulatory reasons. The change impact on the business is high, especially if current processes undergo a major change as part of the implementation or if brand-new processes are introduced. Normally, the timelines for Greenfield implementation could be longer due to probable implementation in phases. Detailed testing needs to be carried out with the involvement of the business so that the business is conversant with the new S/4HANA system. Overall, initial costs would likely be higher for the Greenfield approach when compared to other options.
The time to decide is now
The SAP landscape is changing rapidly, and the cost of inaction is rising. With ECC 6.0 support ending by December 2027, organisations can no longer afford to delay their migration plans.
Whether opting for a fast Brownfield conversion, a phased Bluefield transition, or a transformative Greenfield implementation, the key is to start planning today. The right path depends on business goals, resources, and long-term vision. But whatever path is chosen, acting now will save time, money, and stress in the long run.
Need help navigating your S/4HANA migration? Contact our team of experts for a personalised assessment and tailored recommendations.
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