Rethinking the path to SAP S/4HANA: Is Selective Data Transition a muddy field?

SUMMARY: When navigating the path to SAP S/4HANA, are you only considering Greenfield or Brownfield, or have you thought about a Hybrid conversion or Selective Data Transition (SDT)? And is the latter a ‘muddy field’ approach, or is it simply misunderstood? In this blog, Jamie Neilan explores why the traditional approaches often fall short, and how many more options open up with a Hybrid mindset. He explainsthat SDT and Hybrid options are highly targeted, deliberate and flexible strategies that allow you to focus project investment on where business value can be found, and how EPI-USE Labs offers a targeted, software-driven migration approach called PRISM.

For many organisations, the journey to S/4HANA feels like a choice between two imperfect options. You either wipe the slate clean by accepting the massive cost and disruption of a full Greenfield rebuild, or you take the speedy Brownfield approach where you lift and shift years of technical debt into a new system just to meet the 2027 deadline.

In 2026, neither of these feels like a big win. You need your historical data for analytics and compliance, but you definitely don’t need 15-20 years of obsolete data slowing down your shiny new HANA database.

Then there is the middle ground – often called a Hybrid conversion, Selective Data Transition (SDT) or Bluefield approach – that is increasingly becoming considered by organisations with complex landscapes. In a recent article by the Register, the author referred to it as a ‘muddy field’ approach, implying a middle ground without a clear definition.

This got me thinking… Is the approach actually muddy, or is it simply misunderstood?

To understand why the SDT approach is necessary, we have to look at why the traditional approaches often fall short.

• Brownfield is often the default for organisations under time pressure. This lift-and-shift method promises speed, but it migrates old baggage, redundant configurations and inefficient processes into the new environment. You aren’t modernising; you are simply moving to a more expensive platform that remains constrained by legacy processes.
• Greenfield, on the other hand, is a clean slate. It promises a fresh start, but it comes with a heavy price tag and demands change management. Organisations who chose this approach often incur significant cost to rebuild processes that already work perfectly well. It carries high risk, long timelines, and forces you to put away your historical data that might still have value for compliance or analytics.

Read more about the approaches: Greenfield, brownfield or hybrid: What are your options when moving to S/4HANA?

Is the SDT approach really a muddy field?

It’s not entirely wrong to brand SDT a ‘muddy field’ to highlight the complexities of taking elements of both Greenfield and Brownfield designs into your solution. IT leaders fear that by trying to do both, they risk losing control by carrying over legacy baggage while failing to achieve true innovation. In fact, attempting an SDT approach without the right preparation or solutions can indeed feel like wandering into a messy, muddy field.

However, the Greenfield terminology is misleading. Unless you can adopt standard processes 100%, you’re going to also muddy up that field quite quickly. In all cases, clarity in planning and reasoning is needed.

The link between selective data, transformation and business process is also often overlooked. Brownfield and Greenfield paradigms are more about business process than data. In fact, you can take a totally Brown or Green process approach and still, in every instance, be selective with data – provided you have the right solutions.

A Hybrid approach opens up your options

In a Hybrid mindset, many more options open up. Targeted business change makes historical data loading easier and more automated than an entirely Greenfield approach; while the disconnection of shell-setup from data transition allows for configuration alterations to be made before data is loaded and transformed to match. This means not only can you adopt change just where your business sees financial or operational benefit; you can also fix configuration (that may have plagued you for years) that has nothing to do with standard processes, and is hard to fix during business as usual (such as your Company Code setup, CO area design, CoA setup, G/L key setup, Document Splitting types, etc.).

A totally technically pure traditional Brownfield won’t do this; while a Greenfield setup can address these issues, but potentially goes a very long way past them. It doesn’t matter what colour your conceptual field starts out like. Mud will surface. The mud comes from the sheer complexity of SAP data environments.

How can you choose the right solutions for data transition?

When it comes to choosing solutions to help ensure data transition matches your transition solution design, care is needed. SAP provides a good aid with the Business Transformation Center (BTC), but BTC alone doesn't support all SDT options or high-complexity transformations; while other tools that only aid semi-manual processes often struggle to isolate specific datasets without breaking the business logic. With manual mapping or standard scripts, complexity can spiral when you are trying to transition the data you need. This is how you end up with a Frankenstein system where the lack of clear data continuity results in a system that is neither truly modern nor historically reliable.

So, this muddy label is a fundamental misunderstanding of what the SDT approach actually is. In reality, every major transformation project has its ‘muddy’ phase, just as fields are always muddy at least once a year. The difference lies in how you choose to navigate that field. Far from being a confused compromise, SDT and Hybrid options are considered highly targeted, deliberate and flexible strategies that allow you to focus project investment on where business value can be found.

The best of both worlds: A targeted, software-driven migration approach

This is where EPI-USE Labs’ solutions like PRISM for S/4HANA change the narrative. PRISM enables the project to include both Greenfield and Brownfield elements through a software-driven migration approach. It provides the surgical precision required to handle complex data extractions, to transform data in-flight and to stream data directly into SAP Data Migration Cockpit (DMC) when objects need a functional load (for example, to merge systems, or when you’re nearer the Green end of the spectrum).

This allows you to selectively move only the data, configurations and processes that still serve your business – transforming history to meet new configurations – while leaving the rest behind.

Benefits of the PRISM approach

This approach through PRISM introduces several structural benefits:

• Move only what matters: Filter out outdated or irrelevant data and bring forward only what adds value. Improved data quality too.
• Single-system selective transitions: Create a completely automated, software-executed solution for go-live.
• Phased migrations: Transition by business units, functions or regions while keeping ECC and S/4HANA running in parallel.
• Reduce data footprint: With selective data move to S/4HANA, it reduces HANA storage costs, simplifies compliance, and removes the need to keep legacy ECC systems online just to view old records.
• Transform your landscapes: Consolidate systems, split company codes, or modernise finance to maintain business continuity.
• Unified software suite: One platform to handle your ERP core, your HCM/Payroll and your analytics data as you move to the new world of S/4HANA, SAP SuccessFactors, ECP and BDC.
• Accelerate time-to-value: Focus on the areas that matter most, minimise disruption, and avoid the cost of rebuilding everything twice.
• Reduce business disruption: SDT allows business operations to continue with optimised downtime, ensuring the business keeps moving while the new system is tested.
• Optimise non-production systems: Optionally reduce your non-production instance sizes even further with our Test Data Management options and embed non-production data scrambling into your estate from day one.
• Decommission legacy systems: Using EPI-USE Labs’ Archive Central solution, you can decommission any historical data you don’t want to take, giving you secure, role-based access to legacy data.
• AI readiness: Selectively migrate high-value data that will support future machine learning and AI-driven innovation.

The verdict: SDT is not a muddy field; it’s a structured path for organisations that need both control and flexibility

As organisations face this unique chance to redesign their data landscapes, the most effective transformations come from aligning technical decisions with business reality.

The SDT approach through PRISM allows organisations to

• move what creates value
• retire what does not, and
• modernise without unnecessary disruption.

For complex landscapes, that balance is often what determines whether a transformation succeeds. Don’t let muddy labels dictate your strategy.

Where should you start?

EPI-USE Labs offers a free PRISM assessment, providing a data analysis to give you further insights. We can also provide a more detailed functional analysis to give you both a technical and functional overview to help you identify strategic paths. In compliance with data privacy laws, the transport applied doesn’t expose any confidential system data.