Greenfield, brownfield, hybrid or BLUEFIELD™: pick your path to SAP S/4HANA

May 14, 2021
  • IT
  • SAP

When it comes to SAP S/4HANA implementations and migrations, plenty of terminology is flying around. Different terms that mean the same thing, similar but unrelated words, and overlapping definitions … All of these make understanding the language of SAP projects tougher than it needs to be. In this blog post, our in-house SAP S/4HANA expert Folker Lamote lays it all out for you – including the pros and cons.

Both the terms ‘greenfield’ and ‘brownfield’ aren’t just used in IT. “They are pretty common, especially when it comes to investments – most people are already familiar with them. When it comes to SAP S/4HANA implementations, they mean specific migration approaches.

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Greenfield strategy

Start out with a clean digital slate

In the case of SAP S/4HANA implementations, a ‘greenfield’ implementation means starting from scratch with a completely new system without taking anything from the past with you. It’s a green field, untouched by previous developments.


The pros

  • Without a doubt, a greenfield implementation is the easiest way to get started with SAP S/4HANA. In some companies, the legacy systems were set up in such a way that they are hard to manage, with lots of custom coding, ad hoc solutions and different configurations. With greenfield, you can just sweep aside this unsortable, non-upgradable disarray and start all over again.
  • There’s also a business reason why a greenfield approach is often favored. Businesses are never static – chances are that your organization has changed over time and you used to rely on processes that are no longer valid. A company might have shifted from providing goods to offering services, or your geographical footprint has been restructured. In the case of a company with multiple sites, a greenfield implementation can be approached in a phased way. However, you’ll need temporary solutions for inter-company movements and possibly parallel systems running at the same time.

The cons

  • The initial cost of a greenfield SAP S/4HANA implementation will be higher than other approaches. This is because you need to redesign the processes that were working well with the old system. Take invoicing, for example: you have to recreate your perfectly nice invoice layouts from the beginning.
  • Your company will also “lose” its historical data. It takes some thinking ahead to maintain access to this data and to ensure legal compliance. But that generally isn’t a big deal or a major detractor.

Brownfield strategy

Keeping the same structure, improve performance

In contrast, a brownfield implementation of SAP S/4HANA always begins with the existing system – it’s just that some important elements are changed.

Think of a car, it’s a little far-fetched, but imagine needing a full engine replacement. You still have the same car with the same history and the same mileage, the same look and feel. Nothing changes for the driver other than performance improvements. Of course, you can take it a step further and add a completely new dash that displays more information in a better, more intuitive way.

This analogy corresponds to a brownfield migration of SAP S/4HANA that includes SAP’s innovative new interface, SAP Fiori. Users can use the same GUI interfaces they’ve relied on for years or choose to embrace Fiori, which introduces a lot of benefits and added value such as enhanced user experience.


The pros

A brownfield migration is less costly, since the things that work well for your company do not have to be rebuilt from scratch. Some customers might choose small technical refinements of existing functionality and apps, but the migration is a lot lighter. You also get to take your master data with you without having to extract and load it into an entirely new system – it all happens automatically during the migration.


The cons

The main issue with a brownfield migration is that it has to be done all at once, known colloquially as a “big bang”. If your company has a limited tolerance for downtime, a brownfield can be difficult. And while the migrated system includes the full scope of SAP S/4HANA advantages, you can’t drastically overhaul the way you have set up your system. 

The modern way of implementing keeps the core ‘clean’ – developments are executed on a specific platform and not in the core. It’s important to note that applying this approach to a migration requires quite a bit of rework, but it could be done in a second phase.

Hybrid strategy

Making much-needed changes but keeping your data

A hybrid approach combines elements of greenfield and brownfield SAP S/4HANA implementations for specific reasons.

A perfect copy of a customer’s existing system will be made while removing their data from it, keeping the configurations and custom development efforts, and migrate it to SAP S/4HANA. The migration itself is easier, since it allows you to make changes to your configurations. But you always have to load the data again – that’s the big disadvantage.

If an organization really needs to make core changes to their environment, a hybrid approach is suitable. This is because they get to reuse a lot of things you’ve built, and you avoid the longer downtime inherent to a brownfield migration. Since the new system is running in parallel with the old, there’s a cutover time of a couple hours rather than a few days.

Introducing the BLUEFIELD™ approach

Getting the best out of greenfield and brownfield approaches

We have teamed up with world-leading software solutions provider SNP to offer a new migration approach that relies on its CrystalBridge® software. The result is a data transformation platform that enables companies to both migrate to S/4HANA and revise their setup through a single project.

This approach is suitable for enterprises that:

  • prioritize limited risk and project length.
  • want to split or merge systems and combine this with a move to S/4HANA to limit the effort needed.
  • seek to make drastic changes to their system without losing their data history.
  • require a very large installation, enabling them to avoid a ‘big bang’ or if their database is unusually large – leading to excessive downtime in the case of a migration.
The best way forward? Let's have a chat. We’ve got a wide range of SAP S/4HANA implementations under our belts and have the insights and experience to ensure that your transition is the very smoothest possible.
- Folker Lamote, SAP S/4HANA expert, delaware

In summary


GreenfieldBrownfieldBLUEFIELD™
Pros- Easier to implement
- Supports new business model and operations		- Less costly
- Able to add new functions
- Maintain historical data		- Shorter downtime
- Maintain historical data
- Able to make some customizations to the core system
Cons- More costly
- Loss of historical data from legacy system		- Significant downtime during system cutover

There is no one-size-fits-all solution when it comes to an SAP S/4HANA implementation

A company’s industry, organization and history, as well as the structure of its IT environment, are major factors influencing its ideal path to SAP S/4HANA.

Moving from an ECC system to a greenfield S/4HANA system will not be drastically different for users. This may be a different story if you’re moving from a legacy system like AS400 to SAP. Even so, there are still ways to preserve familiar ways of working.

"The best way forward? Come talk to us. We’ve got a wide range of SAP S/4HANA implementations under our belts and have the insights and experience to ensure that your transition is the very smoothest possible,” Folker concludes.

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