SAP introduced the Clean Core concept a few years ago as a key strategy for S/4HANA Cloud. While many of my customers have come across the term, they may not fully grasp its true meaning. This blog aims to clarify what SAP Clean Core is all about and how it impacts their business.

What is Clean Core?

According to this webpage on SAP.com, SAP defines Clean Core is a set of guiding principles that support continuous business transformation by designing agile, innovative and efficient ERP systems. Over the years, customization approaches in SAP have evolved—from user exits to enhancement points, from RFC & IDocs to OData & REST APIs, from ALV reporting to CDS & Embedded Analytics, and from dialog programming to Fiori extensibility.

As S/4HANA continues to advance, incorporating newer technologies like AI, it is crucial to adapt and refine how organizations customize their SAP systems. Clean Core applies specifically to S/4HANA Private Cloud, ensuring a streamlined system while allowing customization through modern, cloud-compliant extensions. S/4HANA Public Cloud, by definition, remains “clean” due to its built-in constraints on custom development.

For S/4HANA on-premise customers, adopting the Clean Core principles can be a strategic move—especially for those planning to migrate to S/4HANA Cloud in the future or intending to upgrade their S/4HANA version on a regular two- to three-year cycle.

Why do we need Clean Core?

The philosophy of keeping an SAP ERP system close to standard by prioritizing configuration over customization has been a best practice for over 15 years, dating back to the introduction of ECC 6.0. SAP customers who implemented ERP in the 1990s or prior to ECC 5.0 or 6.0 often had extensive customizations due to the limitations of earlier versions. These modifications were necessary to compensate for missing functionality.

Customers whose first SAP version predates ECC understand the challenges of upgrading, especially with heavy customizations, which require rigorous testing to ensure compatibility. In contrast, customers who started with SAP ECC benefited from SAP Best Practices, which provided pre-configured business process scenarios, reducing the need for customization. They also adopted modern development approaches of the time—such as using SmartForms instead of SAPscript.

The advantages of limiting customization remain the same today: a smoother upgrade process, the ability to leverage new SAP innovations and functionalities, enhanced system performance, and a lower total cost of ownership (TCO).

The growing discussion around Clean Core stems from the increasing expectation that SAP customers should upgrade their systems more frequently than in the past. I don’t disagree—organizations invest significantly in SAP through annual maintenance or subscriptions, funding continuous innovation and product enhancements. With technology evolving at an unprecedented pace, staying current ensures businesses can leverage the latest features, performance improvements, and AI-driven capabilities.

That said, if an SAP customer is reluctant to upgrade their system every few years, it raises an important question: Why remain on SAP if not committed to modernization and innovation?

Implementing Clean Core strategy?

Now that we've explored the what and why of Clean Core, let’s turn to the how and when.

The first step in your S/4HANA journey is to evaluate your current landscape of customizations. Tools like SAP Readiness Check and ABAP Test Cockpit can support this assessment, but it starts with compiling a comprehensive inventory of your custom objects—custom fields, tables, user exits, BADis, enhancement points, interfaces, reports, outputs (e.g., SmartForms), and more.

Once your list is complete, identify which objects can be replaced with standard functionality, addressed through cloud extensions, or redesigned using modern approaches—for example, replacing custom ALV reports with CDS Views and Embedded Analytics. Prioritize which items require immediate remediation and which can be tackled incrementally.

Next, get acquainted with SAP Business Technology Platform (BTP) to understand how side-by-side extensibility can modernize your environment. Consider using SAP Build for creating custom applications and SAP Integration Suite to update legacy interfaces (like those built on RFC or batch processing).

Finally, it's essential to set realistic expectations. Achieving a Clean Core is not a one-time project—it’s a long-term, strategic commitment. Depending on the size and complexity of your existing customizations, this transformation may take several years, evolving over multiple phases of your S/4HANA roadmap.

Clean Core: More than Just Customization

A common misconception is that Clean Core is solely about customization—or as we should now refer to it, extensibility. In truth, the ERP core encompasses five foundational components: Processes, Data, Integration, Operations, and Extensibility. The Clean Core philosophy can and should be applied across all of them.

Take data, for example—a critical pillar that often gets overlooked. Evaluating and improving both master and transactional data is essential to ensure high data quality. Doing so not only enhances operational efficiency today, but also positions your system to fully leverage innovations like artificial intelligence in the future

Final Thoughts

In conclusion, the Clean Core approach isn’t just a one-time project milestone—it’s a long-term commitment to keeping your SAP environment lean, agile, and future-ready. Whether you’re planning a move to S/4HANA or are already live, adopting Clean Core principles now will position your organization to better handle upgrades, embrace innovation, and stay aligned with SAP’s rapid development cycle.

As we've explored throughout this blog, Clean Core has been a guiding philosophy for some time—but its importance has never been greater. The key difference today is that it must be treated as an ongoing practice, embedded into your strategy beyond the initial project go-live.

At CONTAX, we’re here to help you navigate this journey. Whether it’s adopting Clean Core practices or leveraging SAP BTP services, our expertise can guide you every step of the way. Reach out to us @ info@contax.com to learn how we can support your transformation.