The concept of Clean Core has emerged as a key strategy in modern SAP projects. But what exactly does it mean? Clean Core refers to an approach that aims to keep the standard SAP core as “clean” as possible by avoiding direct modifications to the core system.
The objective is to ensure greater system stability, simplify upgrades, and guarantee long-term maintainability of the SAP environment. This requires rigorous practices, the right tools, and clear governance around extensions and customizations.
In this article, we will explore the five key pillars of Clean Core, with a special focus on extension management. To illustrate these principles in practice, we will share insights from our SAP Technical Manager, Fatma Ben Zhioua, who has guided several clients across diverse industries in implementing this approach.
The Five Pillars of Clean Core
Here are the fundamental principles that form the foundation of this approach:
Standardization
This pillar focuses on aligning solutions with SAP standards by adopting a fit-to-standard approach, activating Best Practices, and minimizing deviations (fit-gap).
Data
The goal is to ensure high-quality data through cleaning, deduplication, and structuring—critical activities during migrations or system integrations.
Extension
Extension allows businesses to enhance SAP solutions while following best practices. There are two main types of extensibility:
- In-App (within the SAP system)
- Side-by-Side (via SAP BTP)
Integration
Integration is a strategic pillar. SAP promotes a fluid, holistic architecture connected to the ecosystem via APIs and event-driven logic (asynchronous, real-time).
Processes
The aim is to make processes efficient and automated, reducing manual and repetitive tasks.
Practical Insights: Integrating Extensions in a Clean Core Approach
Our SAP Technical Manager, Fatma Ben Zhioua, shares her experience implementing Clean Core across multiple clients from different industries. She explains how to apply Clean Core principles depending on the available extension options.
Before going further, it is important to understand the project context: is the deployment in Public Cloud, Private Cloud, or On-Premise? This architectural choice plays a critical role, as it directly determines which extension options are compatible with a Clean Core strategy.
In-App Extensions
With SAP S/4HANA Private Cloud or On-Premise, it is still possible to develop using classic ABAP. For technical consultants, it is therefore essential to anticipate this from the design phase and define a Clean Core implementation guideline, especially for recent versions such as S/4HANA 2023.
In-App extensions within this approach rely on:
- Key User Extensions (CFL, CDS browser…)
- BAdIs Cloud
- RAP Extensions (RESTful ABAP Programming Model) – a central component of modern extensibility.
👉 No more user-exits or implicit/explicit enhancements!
Side-by-Side Extensions
SAP provides a clear guide to help businesses choose between In-App and Side-by-Side extensibility: Extend SAP S/4HANA in the cloud and on-premise with ABAP-based extensions.
The Side-by-Side model relies on SAP Business Technology Platform (BTP), which enables:
- Developing applications via SAP CAP or ABAP Cloud
- Leveraging services such as SAP Build Process Automation (formerly PBA)
“ Today, with the rise of the Cloud, companies are looking for solutions that are both robust and scalable. The Clean Core strategy has become essential to ensure the scalability of IT systems and operational performance.
Having a ‘clean core’ is essential—it does not mean limiting yourself to the standard. That is where SAP BTP comes in: enriching the ERP with complementary applications without modifying the core. ”
Fatma Ben Zhioua, SAP Technical Manager – Aymax
The Clean Core approach should not be seen as a constraint. Of course, it requires adopting new technical practices, architectures, and syntaxes. But above all, it represents a unique opportunity to build a robust, scalable SAP architecture fully aligned with SAP’s standards.
Article written in collaboration with our SAP Technical Manager, Fatma Ben Zhioua.
FAQ
What is SAP Clean Core ?
SAP Clean Core is an approach that keeps the SAP S/4HANA core as standard as possible by shifting all custom developments into isolated extensions such as BAdIs, SAP BTP extensions, or user exits.
What is the main objective of SAP Clean Core in S/4HANA ?
The main goal of SAP Clean Core is to reduce technical debt, simplify upgrades, and accelerate the adoption of SAP innovations—while ensuring system stability and performance.
Does SAP Cloud ALM help maintain a Clean Core architecture ?
Yes. SAP Cloud ALM provides guided processes, quality checks, and centralized governance for extensions, ensuring alignment with Clean Core principles.
Is Clean Core compatible with RISE with SAP ?
Absolutely. RISE with SAP embeds the Clean Core methodology into its roadmap, leveraging SAP Activate and cloud services to guarantee a standardized and agile transition to S/4HANA
Which SAP tools support Clean Core ?
Key tools include:
- SAP Extension Suite and BTP Guidance Framework for off-core extensions
- Process Authoring in Cloud ALM for modeling and versioning workflows without impacting the core
Can I migrate to Clean Core after years of SAP customizations ?
Yes. By analyzing existing code through a Clean Core Analysis, remediating it, and rehosting developments on SAP BTP or as extensions, companies can progressively standardize their SAP core.
Is it possible to adopt Clean Core progressively in an existing system ?
Yes. Contrary to the myth that it requires starting from scratch, organizations can stop injecting new custom code into the core and gradually refactor existing developments into extensions, supported by SAP tools and best practices.
