Clean Core and Extensibility: Key User, ABAP Cloud, Side-by-Side and the Levels A to D
As of 2026-10-30
SAP grades every extension of SAP S/4HANA on four clean core levels, A to D, instead of the old three-tier model. This module shows how to reach Level A with key user apps, on-stack ABAP Cloud and side-by-side apps on SAP BTP, how to read the Cloudification Repository, and how to govern the result with ABAP test cockpit checks and the SAP Cloud ALM level view. You classify eight sample extensions, design a key user field and an event extension, and learn why analytics extraction must read released CDS views only.
What you will learn
- Classify an extension on level A, B, C or D using the lowest-ranked technology rule
- Look up an object in the Cloudification Repository and read its release state and successor
- Choose between Custom Fields and Logic, ABAP Cloud and a CAP app for a given requirement
- Configure a destination in the SAP BTP cockpit for a released OData API call
- Write a one-page extension register with evidence and remediation
Concept overview: clean core in 2026
Clean core means that every customer extension of SAP S/4HANA reaches SAP code only through interfaces SAP has released and promises to keep stable, so that upgrades do not break custom objects. Since August 2025 SAP expresses this with four extensibility levels, A, B, C and D, and no longer with the older three-tier model, which SAP describes as sunset in its extensibility guidance published 12 August 2025. The unit being graded is the extension, not the person or the project: every custom object gets a level, and the extension is rated by the lowest-ranked technology it uses.
Prerequisites
- Basic knowledge of SAP S/4HANA data model and CDS views (see M414)
- Awareness of SAP S/4HANA editions (see M412)
- Access to an SAP BTP trial or the SAP Cloud Appliance Library for the validation steps
Outcomes
- Name the four levels and give one typical object for each
- Explain why a BAPI wrapper is Level B and a direct table read is Level C
- Describe the three routes to Level A and when each applies
- Explain how SAP Cloud ALM shows levels from imported ATC results
- State why analytics extraction reads released CDS views only
Full module with the Consultant plan — €19.90/month. The full module adds: the decision framework · the end-to-end scenario walkthrough · the KPI scorecard · the anti-patterns · the code blocks · the knowledge check · the diagrams.