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Brownfield or Greenfield? All Paths Lead to S/4HANA

23 .10 .2020

Topics:  SAP | S/4HANA

Green field and brown field

SAP S/4HANA is on everyone's lips. The new technology, which is intended to support the user in all aspects, has flooded the business world, at least as far as advertising goes. In addition, businesses are under pressure – even if the termination of mainstream maintenance for SAP ERP 6.0 and SAP Business Suite 7 was postponed, from 2025 to end of 2027. For many users, it has become clear that the old SAP environment must be migrated to S/4HANA, and that this change must not long be postponed. But what is the best way to migrate the legacy data? What options does a company have for migration from the existing SAP environment? What is the difference between the "greenfield" approach and the "brownfield" approach, and are there any other options? In this article, we will discuss the most common migration procedures and the challenges they present.

What is the status quo at your company?

An S/4HANA migration starts with an analysis of the current system. The process steps to come can only be planned once the baseline situation has been assessed. The analysis should take all functions currently in use into consideration. For instance, does your company use lots of proprietary development, which would become obsolete if SAP S/4HANA technologies were to be implemented? Or, on the other hand, would it be possible to streamline more processes—ones in financial accounting or purchasing, for instance—by using the new technology?

You may find that the layout of your current SAP system ends up severely constraining your options, perhaps only allowing a single path of migration. In any case, the analysis you perform will lead you to the target, and your method of migration will be set accordingly. Regardless of the direction you ultimately settle on for migration, one thing should always be planned on: cleaning up the master data and the processes.

Path 1 Greenfield - Clearing the way for standardization

Installing a new ERP system may also imply movement in the direction of standard processes. The greenfield approach would signify an implementation of SAP S/4HANA from scratch. When setting up a fresh SAP S/4HANA system, only basic configuration is performed at the beginning. Everything else has to be configured during the implementation project according to the customer's requirements. With a fresh "green field" to work with, a company can free itself from old burdens. Particularly in system environments such as outdated SAP systems, working from a clean slate in this way has proven to be an ideal means for a migration.

A new implementation allows a company to reevaluate established business processes and align them to the standard. When taking this path, certain issues should be brought to the table: whether all existing programming and Z transactions are essential, whether they might be mapped through narrower processes within a setting such as SAP Fiori, and so on.

Path 2 Brownfield - Upgrading, not migrating

A complete overhaul is not always necessary, nor is it always the right path for a company. Over the course of a migration, it is also possible to follow a so-called brownfield approach. With this approach, the existing SAP system forms the basis for an additional migration—even though the existing system remains in place, the transition is to a different product family, for which reason SAP does not refer to it as an upgrade.

The brownfield migration procedure is often employed by companies that use more up-to-date SAP systems and have already adapted and simplified their processes internally. At first glance, the fact that these prerequisites have been filled lends this type of S/4HANA migration the appearance of being easier. However, the actual complexity comes out over the course of the implementation, and a brownfield migration often turns out to involve significantly more effort than originally assumed.

The preparations for a brownfield migration are similar to those for a greenfield implementation. A data clean up should take place and the source system has to be analyzed. To lay more solid ground, tools from SAP can be used to perform an advance check of the systems for the migration. These tools check the system and its code for compatibility.

Path 3 - Transforming the system landscape on the way to S/4HANA

A third path to S/4HANA is to transform the system landscape. In this scenario, SAP ERP systems that used to be operated independent of each other are merged into a common S/4HANA system. The implementation of the update to the new system is based on one of the procedures described above. One reason to opt for this route would be to reap the benefits of the new technologies provided by S/4HANA. S/4HANA's new compression algorithms and its significantly accelerated speed in processing are especially advantageous when the scenario involves large amounts of data. When the systems are consolidated, replicated data on different SAP systems can be removed.

All paths lead to S/4HANA

With an S/4HANA migration, there is no right or wrong way. Experience in migrations varies greatly from company to company, and each company starts a new migration from a very individual starting point. Some experts claim that a solid S/4HANA system can only be achieved by using the greenfield approach.

However, this is not necessarily the case if sufficient preparatory work has already been carried out in the existing SAP system. This is the reason why so many companies wish to take the brownfield approach. If S/4HANA is to put out the desired level of performance, a sufficient minimum of computing power must be provided for. Therefore, as part of the changeover to the new system, it may make sense to integrate cloud services. They can deliver performance, availability and scalability with little or no effort. SAP and other data centers offer different variants for outsourcing infrastructure to the cloud.

If the goal is to establish standard processes, it would be wrong to take effort as the reigning criterion when planning a migration; rather, the opportunity to rethink company processes should be at the forefront. Migrating to S/4HANA requires sufficient preparation and structuring. Taking the proper steps, however, puts a standardized system and all the benefits that accompany it in place.

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