SAP S/4HANA Migration

How to Achieve Clean Core:
Cloud Strategy Sets the Course

Many SAP customers on the verge of migrating to S/4HANA are asking themselves the following question: What will happen to our custom developments? Our advice: In any case, it is worth investing in clean core. Your own objective and cloud strategy will determine which approach is right for you.

For a long time now, many SAP user companies have used their SAP ERP system not only to map standard processes and functions, but also as a development platform. The user/customer exits available in ABAP, the enhancement framework, BADIs (Business Add-Ins), BAPIs (Business Application Programming Interfaces), modifications, and so on offer comprehensive enhancement options to easily customize the standard SAP system – integrated with access to all available SAP data.

Generally, this is not done for the fun of programming, but rather because a company needs to map or expand the unique selling proposition or their own competitive advantage through the use of customized digital processes. Consequently, several thousand lines of custom code, customer-specific objects, modifications – and therefore also numerous technical "corpses" – have accumulated over time. In the ABAP world, old, revised and obsolete source code is very rarely deleted. Instead, it is usually carried along for years and years.

Most SAP user companies now face the challenge of having to migrate an SAP ERP system, which has been optimized and expanded over the years to meet their own needs, to S/4HANA. As a result, they are asking themselves whether, and to what extent, a cleanup of customer-specific enhancements in their system is necessary. The experts believe that the cloud strategy favored by a customer when migrating to SAP's new Business Suite is decisive here.

What Is the Role of the SAP Business Technology Platform (BTP)?

As confirmed by DSAG, two worlds are currently colliding in the German SAP community. On the one hand, you have SAP, which now delivers all innovations and new products solely in the cloud, thereby putting its customers under pressure to make the move. On the other hand, you have SAP user companies that are reluctant to move their competitively advantageous data and processes to the cloud and have concerns regarding the flexibility and integration they have become accustomed to.

Let's first take a look at SAP's technological response to these concerns, namely the SAP Business Technology Platform (BTP). With this platform, SAP continues to promise its customers the flexibility to realize custom developments and system enhancements in a protected environment:
"Tap the power of SAP Business Technology Platform (SAP BTP) to extend and personalize SAP applications, integrate and connect landscapes, and unleash business users to connect processes and experiences, make decisions with confidence, and drive business innovation."

Why Are Clean Core Strategies Important?

If SAP's goal is to bring all customers into the cloud sooner or later, the private cloud (e.g. S/4HANA Cloud, private edition) seems to be an interim solution (or loophole). In the long term, however, SAP is pursuing a public cloud strategy so that it can deliver (that is, sell) innovations and new products promptly without any obstacles such as customer-specific source code or even modifications.

Like it or not, any long-standing customer with the relevant experience and foresight knows that resistance is futile. Companies must decide whether to switch to non-SAP products or face up to this situation early on and develop strategies to achieve clean core. This includes concrete considerations as to which ABAP custom developments are actually still needed ("clean up") and which can be mapped via an SAP BTP solution or app ("redesign"). It is already possible to start both measures and technically implement them today.

What Are the Benefits of Clean Core?

Almost all SAP user companies with a large number of custom developments generally shy away from a release upgrade because this comes at a high cost due to the technical checks (SPAU, SPAM) and testing effort involved. With clean core, on the other hand, the technical tests are almost fully eliminated and the standard SAP processes can be easily mapped using a test automation tool. All cleanups therefore contribute toward rationalizing the operation of an SAP system.

One such example is a reduction in custom code, which, in turn, reduces the amount of maintenance work involved and therefore saves on costs. These efforts do not fully cease when the ABAP customer code is moved to side-by-side extensions in the BTP or other platforms. Rather, the workload shifts to modern, easier-to-maintain development environments.

Potential savings through Clean Core

So is clean core always beneficial? Not quite! The truth is that relocated developments, apps and new (SAP) products are increasing the number of interfaces and integration issues.

What Is the Recommended Procedure for S/4HANA On-Premise?

Our current perception is that most (German) user companies initially want to migrate to S/4HANA On-Premise and not to one of the S/4HANA Cloud editions (Private or Public). This decision must undoubtedly be made on both a case-by-case and individual basis. When, or even better, before migrating to S/4HANA On-Premise, it is advisable to take a critical look at the existing custom code: Are all ABAP custom developments really necessary? Or does it make more sense to relocate individual (for example, older or encapsulated) developments in Fiori apps to the BTP?

On the one hand, such a relocation enables the company's own development resources to cautiously edge toward the new technologies while also enabling the individual departments to familiarize themselves with the new interfaces. Having one less custom object in the SAP space reduces the workload in the long term and represents an investment in the future. However, the relocation license costs must be taken into consideration – indirect use of SAP software can also fall at the feet of users.

Why Should SAP Customers Act at All?

As these comments show, an increasingly complex world has no simple answers. This also applies to the topic of clean core: Every step toward this goal should be carefully considered and consciously implemented. What is relatively certain, however, is that "not taking a step at all" essentially means a step backward for your company and is more likely to result in greater challenges in the future. What's more, SAP provides numerous tools for cleaning up custom code. These always provide a good initial overview – starting with the scope of the customer's own objects.

How Can You Benefit from Our XEPTUM Expertise?

Do you intend to migrate to SAP S/4HANA but are unsure what impact this will have on your ABAP customer code? Benefit from our competence and expertise! Our XEPTUM consulting team is familiar with all aspects of clean core and S/4HANA migration. We are happy to support you in designing and implementing the right clean core strategy for you so that your SAP system is free of unnecessary custom code prior to the changeover.

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