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

Greenfield: start out with a clean digital slate

“In the case of SAP S/4HANA implementations, you’d be right in guessing that a ‘greenfield’ implementation means starting from scratch with a completely new system without taking anything from the past with you,” Folker continues. “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 have been 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 mess and start all over again,” Folker explains.
• There’s also a business reason why a greenfield approach is often favored. “Businesses are never static – chances are that your business organization has changed over time and you used to rely on processes that aren’t valid anymore,” he continues. “Maybe you’ve 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 intercompany 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. Folker: “This makes sense because you have 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,” Folker goes on to say. “But that generally isn’t a big deal or a major detractor.”

Brownfield: keep 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,” says Folker. “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, etc. 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,” he elaborates.

The pros
A brownfield migration is less costly, since the things that work well for your company don’t have to be rebuilt from scratch. Folker: “Some customers 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.”