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S/4HANA Clean Core
Master S/4HANA Clean Core with released APIs, extensibility options, ATC checks, custom code migration, side-by-side extensions and upgrade-safe ABAP design.
Overview
Master S/4HANA Clean Core with released APIs, extensibility options, ATC checks, custom code migration, side-by-side extensions and upgrade-safe ABAP design.
Lessons in this topic
- SAP S/4HANA Clean Core and Custom Code Migration Tutorial (Part 1)Understand Clean Core as an upgrade-stability discipline: keep S/4HANA standard as intact as practical, use released extension contracts, govern exceptions and move decoupled capabilities to side-by-side platforms where appropriate.
- SAP S/4HANA Clean Core: On-Stack vs Side-by-Side Extensions (Part 2)Use a consistent Clean Core decision sequence—standard, key-user extensibility, released on-stack extension, released API or side-by-side BTP—before accepting tightly coupled custom code as a governed exception.
- SAP Custom Code Migration: Triage Custom Objects for Clean Core (Part 3)Classify custom code by actual usage, business criticality and dependency risk so S/4HANA modernization targets the objects that truly need retirement, remediation, replacement, redesign or side-by-side relocation.
- SAP Custom Code Migration: ATC Cloudification and Remediation (Part 4)Use ATC as a portfolio and transport governance tool for S/4HANA and ABAP Cloud readiness, prioritizing unreleased dependencies and incompatibilities by real productive usage and business criticality.
- SAP Clean Core: Released APIs vs Direct Table Access (Part 5)Use released business APIs and CDS contracts instead of direct dependencies on SAP internal tables for new clean-core development, especially for updates where direct writes bypass application integrity.
- SAP Clean Core Extensibility: Key User, Developer and Side-by-Side (Part 6)Choose among key-user, developer and side-by-side extensibility by coupling, lifecycle and complexity, using the least invasive released option that satisfies the business requirement.
- SAP Clean Core Risks: Modifications, Enhancements and Unreleased APIs (Part 7)Identify the highest Clean Core risks by dependency type: direct SAP modifications, implicit source enhancements, unreleased APIs and direct writes to standard tables create more upgrade exposure than custom-code volume alone.
- SAP BTP Side-by-Side Extension for Clean Core (Part 8)Choose side-by-side BTP extension when the capability benefits from an independent lifecycle and loose coupling, integrating through released APIs or events rather than recreating tight save-time dependencies outside S/4HANA.
- SAP Clean Core Governance: Standards, ATC and Documentation (Part 9)Sustain Clean Core after go-live with an extension inventory, released-API checks, ATC quality gates, named owners, exception records and periodic review of upgrade-sensitive dependencies.
Interview questions covered
- ATC shows usage of unreleased SAP objects in custom code. What would you do?
- Customer has 200 user exits and wants S/4 conversion. Plan?
- A business requirement can be solved by configuration or a custom enhancement. What should you choose in Clean Core thinking?
- What does Clean Core mean in S/4HANA?
- How would you run a custom code cleanup during S/4HANA conversion?
- What are the three extensibility options?
- How do you sustain Clean Core after go-live?
- A team wants to add an implicit enhancement in S/4HANA because it is faster. How would you respond?
- Using this SAP project situation — A pricing implicit enhancement depended on a local standard variable whose meaning changed during an upgrade — explain Clean Core Risk: Modifications, Implicit Enhancements and Unreleased Objects. What should happen, which concepts or process steps matter, and what common mistake would you avoid?
- Using this SAP project situation — A custom program directly updated a standard order status field and left dependent processing inconsistent — explain Released APIs vs Direct Table Access. What should happen, which concepts or process steps matter, and what common mistake would you avoid?
- Using this SAP project situation — A sales-order custom field was added through key-user extensibility, while an external partner-risk scoring application was built on BTP because it needed third-party data and independent scaling — explain Clean Core and Extensibility Types. What should happen, which concepts or process steps matter, and what common mistake would you avoid?
- Using this SAP project situation — A company completed an S/4 migration with strict clean-core rules, but two years later dozens of new direct-table integrations had appeared — explain Clean Core Governance and Documentation. What should happen, which concepts or process steps matter, and what common mistake would you avoid?
- Using this SAP project situation — A conversion assessment found more than a thousand custom objects — explain Classifying Custom Code for Clean Core. What should happen, which concepts or process steps matter, and what common mistake would you avoid?
- Using this SAP project situation — A supplier-risk dashboard combined S/4 supplier data with an external risk provider — explain Side-by-Side Extension on BTP. What should happen, which concepts or process steps matter, and what common mistake would you avoid?
- Using this SAP project situation — A company wanted a save-time compliance validation — explain Clean Core Extension Decision Framework. What should happen, which concepts or process steps matter, and what common mistake would you avoid?
- Enhancement broke after upgrade. Clean Core lens?
- What is S/4HANA Clean Core?
- How do you build a Clean Core governance model?
- New custom code introduced without Clean Core review. Response?
- A customer wants to modify a standard S/4HANA transaction. How do you keep the core clean?