Clean Core or Lean Core?

What is Clean Core in the Context of SAP?

In the context of SAP, Clean Core refers to a methodology and approach for implementing and maintaining an SAP S/4HANA system. It emphasises standardisation and minimal customisation to ensure a cleaner, more streamlined core ERP system.

What has Happened Historically?

In the early days of SAP ERP systems (like R/3 and ECC), extensive customisation was common, even though discouraged. Businesses often adapted SAP to their specific needs rather than conforming to standard functionalities and adapting their business. This resulted in a surge of custom ABAP programs and Data Dictionary entries, often referred to as WRICEF objects.? While this approach addressed immediate needs, it led to heavily customised systems that became major hurdles during upgrade cycles. The complexity of remediating and testing these customisations often discouraged companies from upgrading, creating a vicious cycle.? Unfortunately, delaying upgrades only compounds the issue, making future updates even more difficult and expensive.

Why is it Important Today?

RISE with SAP streamlines S/4HANA upgrades by placing the execution responsibility with SAP.? This frees you to focus on planning and coordination, ensuring a smooth transition. However, achieving a successful upgrade still relies on a collaborative effort. Fewer customisations mean fewer potential compatibility issues during upgrades, minimising the risk of delays and disruptions. A streamlined core system allows SAP to execute upgrades more efficiently, reducing downtime and overall project complexity. Both you and SAP benefit from a Clean Core approach. You experience less disruption, while SAP can deliver upgrades more effectively. Therefore, while RISE with SAP simplifies upgrades, prioritising a Clean Core remains an essential factor in ensuring a smooth and successful transition to the latest S/4HANA version.

What are the Options?

Achieving a Clean Core is the ideal, but a Lean Core is a practical first step for your S/4HANA journey. Before diving into custom code remediation, explore if S/4HANA's built-in functionalities can replace your bespoke business processes. The Simplification Item Catalogue is a valuable resource that details the impact of transitioning from ECC to S/4HANA, highlighting both potential benefits and drawbacks for your specific processes.

If maintaining some custom development is unavoidable, or an S/4HANA migration isn't on your immediate horizon, consider externalising your code with SAP BTP services. SAP BTP offers a suite of tools like Build, Integration Suite, ABAP in the cloud, and side-by-side extensibility that allow you to re-engineer your custom development outside the core SAP system. This approach minimises the impact on your core system and simplifies future upgrades, beneficial to both you and SAP.

But we can still make approved minor changes to the core. SAP in-app extensibility (inside the core) allows you to extend and customise the capabilities of S/4HANA without significant modifications to the core system itself. In-app extensibility is typically used for making minor adjustments and enhancements rather than large-scale system overhauls. Examples include Fiori elements, field-level enhancements and workflow enhancements.

Imagine the scenario where you have a need to extend a Fiori application to include an additional field on the screen with associated validation and persistency. This is a minor enhancement that could be handled with Custom Fields and Logic (CFL). CFL allows you to create, manage, and deploy custom fields and business logic extensions to various SAP tables and objects.

SAP side-by-side extensibility (outside the core) is a method for extending SAP functionality that goes beyond the limitations of in-app extensibility. It allows you to create entirely separate applications that interact with your core SAP system but run independently on the SAP BTP platform.

Imagine you have a custom-built application within your ECC system, packed with programs, screens (dynpros), and data structures (domains, tables, etc.). Re-engineering this application as a standalone system outside your core SAP ERP could be the answer.

Here's an analogy I like to use to help understand the difference:

• In-app extensibility is like adding an extension to your house that utilises the existing foundation and utilities.
• Side-by-side extensibility is like constructing an outbuilding adjacent to your main house, connected by a walkway or patio.

For further insights on unlocking the potential of SAP BTP, please refer to this article: https://www.dhirubhai.net/pulse/unlock-potential-sap-btp-now-gary-jackson-1puef/

This is just a small sample of what can be achieved with the various extensibility options available in the ever-growing toolset from SAP. Thank-you for reading!