SAP MDG: “Intended to be extended”?

Ronald den Otter - SAP Master Data Governance Consultant

Is Clean Core possible when using SAP MDG?

It is often said that SAP MDG (Master Data Governance) is designed to be customized, as if the standard SAP MDG could never meet an organization’s needs and requirements, and customization is therefore always necessary.

This blog describes the options available to organizations for adhering to the clean core strategy when using MDG.

What is a clean core?

Over time, many ERP systems become complex due to customizations, undocumented or inadequately documented changes, and integrations that are difficult to maintain. As a result, the system becomes less flexible, upgrades take longer, and costs rise.

The clean core approach helps address this issue. It encourages the use of standardized processes that align with best practices and the implementation of strategic adjustments only where differentiation is truly necessary.

By standardizing processes, organizations can more easily transition to the SAP Business Suite, including SAP Public Cloud.

Clean Core is all about minimizing customizations in the ERP system, standardizing processes, and moving customizations to modern, cloud-based platforms. This keeps the ERP system stable, easy to upgrade, cost-effective, and ready for innovation.

A clean core strategy helps companies to:

Becoming more agile. Less complexity means responding more quickly to changes.
Lower costs can be achieved. Less customization makes upgrades easier and more affordable.
Accelerate innovation. New SAP features can be implemented without significant risk.
To ensure better data quality. A standardized ERP system provides more reliable data, which is essential for AI and analytics.

Extensions for differentiation; the clean core level concept

A clean core does not mean that no customizations are allowed. Where an organization needs or wants to deviate from best practices or standard processes, it can use standardized extensions that leave the core of the system untouched.

To determine how well an extension fits within the Clean Core concept, SAP has defined four levels (A, B, C, and D), taking into account stability during upgrades and the architecture.

This approach allows extensions to be evaluated much more precisely than simply as “clean” or “not clean.” However, the general rule remains that SAP BTP (Business Technology Platform) is the preferred location for extensions, as it supports the highest level. At the same time, this classification acknowledges that many systems are complex and helps customers determine their own pace and path on their clean core journey.

The key principle remains: keep customizations separate from the standard SAP code so that upgrades can be performed safely and smoothly.

SAP recommends aiming for the highest possible clean core level, but understands that companies sometimes need more flexibility.

In that case, the clean core level can be lowered to level B, acknowledging that this is a step backward, but one that allows room to meet specific requirements. This includes objects and extension capabilities that SAP has explicitly classified as classic APIs (Application Programming Interfaces), even if there is no formal upgrade guarantee. Examples include many older APIs, user exits, BAdIs (Business Add-Ins), and existing technologies within the SAP platform, such as the SAP GUI (Graphical User Interface) and the ABAP List Viewer Grid.

SAP has developed a tool to determine what falls under Level B and what is classified as a classic API: the Cloudification Repository.

One level lower, Level C, contains objects intended exclusively for internal use by SAP and therefore not for customers or partners. Examples include internal ABAP classes, tables, and function modules. Although they can technically be used, they are not released or supported, and SAP does not guarantee their (upgrade) stability. , SAP refers to this level as “Conditionally Clean,” because extensions are possible under certain conditions without unnecessarily risking the system’s upgrade stability.

Although not recommended by SAP, they are widely used in custom development. For this reason, SAP will introduce a “Changelog for SAP Objects” to inform customers which internal objects SAP has modified, which may cause them to no longer function as expected after an upgrade, so that customers can plan accordingly in a timely manner.

Finally, there is Level D: “not clean core.” This category includes all customer customizations that use non-recommended SAP objects or development patterns, such as classic ABAP customizations (Z-code) and modifications. These make the system not future-proof and complicate a transition to the cloud.

And what about (partner) add-ons? These can provide additional functionality that fits within a clean core, provided they have the “SAP-certified for Clean Core with SAP S/4HANA Cloud” certification.

Is Clean Core an IT party?

Organizations using SAP S/4HANA on-premises or in a private cloud will sooner or later face the question: How can they keep their ERP landscape flexible, upgrade-ready, and future-proof?

SAP’s answer is clear: clean core. However, the impact of this transformation goes beyond just the technology. It is a strategic move that affects the entire organization, with standardization being the key.

Standardization results in, among other things:

Better data quality
Greater consistency across different business units
Fewer errors and discrepancies
Predictable turnaround times
Reliable reports and analyses
Better scalability

Clean Core and MDG

With the introduction of MDG Cloud Ready Mode in SAP S/4HANA 2023, SAP has taken a major step toward a clean core within the MDG domain. Cloud Ready Mode comes with stricter requirements: only customizations that are upgrade-proof are supported. However, this mode is not the right choice for everyone, as it is only suitable for managing business partners. More information can be found in this blog: https://www.avelon.nl/nieuws-blog/whats-new-in-sap-master-data-governance-on-sap-s/4hana-2023

Organizations that use MDG Classic Mode and want to remain future-proof must therefore carefully consider their customization strategy. A balance must be struck between functional requirements and future-proofing.

Recommended approach to adaptation

SAP recommends the following approach within the clean core philosophy:

Key User In-App Extensibility
Customizations in Fiori apps that are available by default. Key users can make customizations themselves, such as adding fields.
Side-by-Side Extensibility
Customizations and extensions developed outside the S/4HANA core, for example on SAP BTP.
Classic Extensibility
Classic extensions that are only used when the alternatives are insufficient, such as BAdIs, enhancement points, and custom code.

The following SAP blog provides guidance on determining the best method: https://community.sap.com/t5/technology-blog-posts-by-sap/recommendation-best-practice-for-sap-master-data-governance-extensibility/ba-p/14282866.

Validations and derivations

Validations and derivations are often used to improve data quality.

The best clean core options for this are BRF+ (Business Rule Framework Plus) and MDG DQM ( Data Quality Management), as they are built without ABAP code and fall under clean core level A. More information on this can be found in this blog: https://www.avelon.nl/nieuws-blog/masterdata-optimaliseren-met-dqm-derivations.

If these are not sufficient, the Validation and Derivation BAdIs can be used. These allow for the creation of more complex logic. These BAdIs are considered to fall under Level B, provided they are used as intended by SAP.

Conclusion: “Intended to be extended”?

Is SAP MDG really designed in such a way that it can be easily customized to meet specific needs? MDG Classic Mode does indeed offer the necessary flexibility for customization, whereas Cloud Ready Mode is more limited in this regard.

But perhaps the question “Intended to be extended?” isn’t the right one. After all, the benefits of a clean core and standardization are significant—for both IT and the business. So it’s better to ask: “Extend or not extend?”

If the standard SAP system cannot meet certain needs or requirements and a customization is necessary, carefully weigh the business benefits against the drawbacks of the customization and use the SAP Clean Core concept to make well-informed and consistent decisions.

Learn more

For more information about SAP MDG or Clean Core, please feel free to contact Sander van der Wijngaart. He would be happy to discuss how SAP MDG can be implemented as part of your organization’s Clean Core strategy.

Clean Core within SAP MDG