This ASUG member blog post was written by Roger Elwell, vice president of Strategic Partners and Alliance at SNP Group.
Ever since SAP announced it was cutting support for SAP Business Suite 7 effective 2027, the need to migrate to SAP S/4HANA platform has taken on renewed urgency. Already, businesses worldwide are in various stages of their own SAP S/4HANA journeys, ranging from actual implementation, to developing proofs of concept, to still sketching out the initial planning. But what’s true for every one of these organizations is that no two migrations will look the same. Every company’s path to SAP S/4HANA is unique and thus requires an approach tailored to its own needs and environments.
While there is no one-size-fits-all strategy to SAP S/4HANA migration, there will be certain boxes to tick off no matter the approach. Is it cost-effective? Does it involve minimal risk? Does it efficiently and securely migrate the necessary systems and data sets? How will it impact longer-term strategic planning around digital transformation? SAP S/4HANA has a major role to play in modernizing an organization’s business systems and processes, so finding a methodology that addresses these concerns is critical.
As a result, businesses tend to coalesce around one of three general migration approaches: brownfield, greenfield, and bluefield. Each path has its pros and cons, and I’ll break those down below, as well as how enterprises might be able to navigate an approach that gets “the best of both worlds” while migrating to SAP S/4HANA.
Brownfield: An Across-the-Board Update
The brownfield approach takes aim at transforming existing systems. It’s a technical upgrade that will update the existing software you have on the books, comprehensively—but indiscriminately—moving data sets, customizations, and other objects to the new platform. Often, more recent SAP adopters (i.e., businesses that have moved to SAP within the past five years or so) will choose to go the brownfield route.
The appeal of brownfield is in its simplicity: it moves the entire existing SAP ECC system to SAP S/4HANA. It’s a thorough and simple lift and shift that preserves the structure you already have in place. It doesn’t rock the boat and it’s easy enough to execute.
That simplicity is also its downside, though. Brownfield doesn’t offer a selective approach, where you can choose what to upgrade and choose what to migrate. Instead, everything about your current system all gets carried over. That means old business processes or unused components that should be retired are still preserved. What could’ve been an opportunity to reassess—examine technical debt, eliminate the processes and systems you don’t need, and only preserve those you do—is traded for a straightforward, across-the-board migration. It effectively leaves you stuck in place with the systems you have, rather than really taking advantage of the new features and innovations that SAP S/4HANA brings to the table.
Greenfield: Implementation from the Ground Up
While brownfield lifts and shifts your existing systems, greenfield takes the opposite tack and starts from scratch with a completely new implementation. Greenfield is a fundamental change, in both function and technical details, from your current SAP implementation, creating an entirely new system with new business processes and configurations. By essentially wiping the slate clean, greenfield provides businesses with a new opportunity for consolidating an array of disparate ERP systems into a cohesive platform, built from the ground up, with brand new and significantly upgraded business processes and configurations.
So, what’s the catch? If brownfield is too reliant on existing systems and processes, then greenfield is overly dismissive of them. It’s one thing if your environment contains a lot of custom code that you’d prefer replacing with the most up-to-date SAP logic. But if there is historical data or configurations that you prefer to use—and maybe more importantly, historical data that you must preserve for regulatory reasons—then greenfield won’t carry it over.
Like brownfield, greenfield offers no opportunity for selectiveness. Both approaches are “all or nothing,” leaving no room to choose what to migrate and what to upgrade. As a result, both greenfield and brownfield limit the final state of your SAP S/4HANA platform.
Bluefield: Pick and Choose What You Want to Migrate
A “bluefield” migration—which falls in between greenfield and brownfield—is ideal for large companies with very complex IT environments. Unlike brownfield and greenfield, which handle SAP S/4HANA migration with a broad brush—either upgrading everything or scrapping everything and building a new implementation from scratch—bluefield allows businesses to be more selective in their migrations.
Selective migrations give enterprises a choice in which data and configurations to carry over. That level of flexibility is an opportunity for businesses to reassess the data, business processes, and customizations that they’ve had accumulating in the background for years. Want to restructure and digitally transform your systems to better capitalize on the features of SAP S/4HANA? Or ditch old processes and configurations that are neither efficient nor useful, but have gotten by thanks to being “out of sight, out of mind?” Taking the selective migration path offers an opportunity to finally tackle these items.
This selectiveness can also be a boon for businesses in industries that must comply with certain historical data regulatory standards. The ability to selectively choose which data to migrate and which to abandon ensures that your SAP S/4HANA migration method won’t inadvertently lose necessary historical data and potentially put you at risk of noncompliance.
Of course, the value of this selectiveness depends on your willingness and interest in wanting to pick and choose particular data sets or configurations to migrate or leave behind. Otherwise, the all-or-nothing approach of a greenfield or brownfield migration may be a more appealing pathway.
Depending on your organization’s needs—like the size and complexity of your SAP platform and the need (or not) to preserve certain historical data sets and configurations, versus the desire to start fresh—a brownfield or greenfield approach may end up serving you just fine. But, luckily, there’s a “best-of-both-worlds” approach available to companies looking for total selective control over their business-critical data and configuration migrations, and performing them within a single go-live project.
Need more help figuring out your SAP S/4HANA migration? Join the ASUG Influence Council focused specifically on migrating to SAP S/4HANA, and for any of our SAP S/4HANA events.