SAP Clean Core Strategy
Enterprise Architecture guide for business transformation, AI readiness, and continuous innovation through SAP's Clean Core framework.
Why Clean Core Exists
The enterprise ERP challenges that made Clean Core not just a best practice, but a business survival strategy.
Excessive Customisations
Decades of custom ABAP — Z-programmes, modifications, and workarounds — create a bespoke ERP that bears little resemblance to SAP standard. Each customisation is unique technical debt compounding with every release.
Technical Debt Accumulation
Custom code written in 2005 using APIs that no longer exist in 2025. Every modification creates a long-term liability that must be paid at every upgrade, patch, and migration. Interest compounds silently.
Complex Multi-Year Upgrades
When 30–40% of business logic lives in custom code, every SAP upgrade requires exhaustive analysis, regression testing, and re-implementation — turning months of work into years, and years into decades.
Slow Innovation Cycles
Heavily modified systems cannot adopt SAP new innovations. New releases, embedded AI, and Joule arrive, but the technical debt prevents their adoption. The gap between SAP capability and customer usage widens.
High Maintenance Costs
Custom code requires custom-skilled developers, custom documentation, custom testing, and custom monitoring. The total cost of ownership grows year over year while delivering diminishing returns.
Blocked AI Adoption
SAP Joule and Business AI depend on standardised processes, clean master data, and released OData V4 APIs. Customised landscapes cannot consume AI features without significant rework — AI readiness requires clean core.
- Average custom code — mature ECC landscapes
- 5,000–15,000+ active objects
- Upgrade cost without clean core
- 18–36 months + significant CAPEX
- Upgrade cost with clean core
- 3–6 months with automated testing
- AI readiness blocker
- Non-standard APIs prevent Joule skill deployment
- Custom code actually used in production
- Typically only 40–60% of objects ever execute
- TCO reduction potential
- Up to 50% lower ERP operating cost
SAP's Clean Core Vision
What SAP means by 'Keep the core clean' — and why it is the foundation for RISE with SAP, GROW with SAP, and the SAP Business Suite.
Upgradeability
Every S/4HANA release can be adopted rapidly — no custom code blocking, no integration breakage, no multi-year remediation projects before you can consume new capabilities.
Innovation Velocity
New SAP capabilities — AI, Joule, Business Data Cloud — are available immediately because the landscape is in SAP-standard state. Your organisation consumes SAP's investment at release velocity.
Structured Extensibility
Business differentiation is delivered through a governed hierarchy of extension methods — not by modifying SAP standard code. Every extension is intentional, documented, and upgrade-safe.
Governance-First
Architecture review boards, ATC enforcement, and API catalogues ensure every extension is intentional, documented, and upgrade-safe. Governance prevents future debt accumulation.
RISE with SAP
RISE with SAP delivers S/4HANA Private Cloud Edition with SAP-managed infrastructure and upgrades. Clean Core compliance is mandatory — SAP manages the platform and cannot support non-standard modifications. ABAP Cloud enforcement is built into the contractual framework.
GROW with SAP
GROW with SAP delivers S/4HANA Public Cloud Edition — a true SaaS ERP with quarterly upgrades. Clean core is structural — Key User extensibility only, no ABAP development, enforced by architecture. Fit-to-Standard is the only viable implementation approach.
SAP Business Suite
The SAP Business Suite — spanning S/4HANA, SuccessFactors, Ariba, Concur, and Customer Experience — requires clean integrations via released APIs and unified Identity across BTP. Clean Core enables suite coherence and cross-suite AI.
The Five Clean Core Dimensions
SAP's Clean Core framework spans five interdependent dimensions. True clean core requires maturity across all five — not just custom code compliance.
Process Clean Core means adopting SAP Best Practices and standard industry processes as the baseline, minimising deviations that require custom development. Every process exception must have a validated, documented business justification.
Achieve 80%+ standard process adoption. Innovation happens via configuration, Key User extensibility, and SAP-provided enhancements — not bespoke ABAP development. SAP Signavio governs process lifecycle.
A global manufacturer reduces 340 custom purchase order variants to 12 standard variants using SAP Best Practices for Procurement, enabling quarterly S/4HANA upgrades and Joule Procurement skills out-of-the-box.
- Hundreds of custom process variants that prevent upgrade automation
- No process baseline — every site runs a unique variant of core processes
- Business unit silos driving contradictory requirements with no governance
- Run SAP Signavio Process Intelligence to baseline current-state process compliance
- Adopt SAP Best Practices (Model Company or Starter System) as the starting point
- Establish a Business Process Excellence Board to govern exceptions and deviations
Data Clean Core ensures that master and transactional data conforms to SAP's standard data model, is governed through Master Data Governance (MDG), and is harmonized to support AI, analytics, and cross-system processes without bespoke transformations.
A single source of truth for all master data entities. Data quality SLAs published and measured. Business Data Cloud (BDC) can consume S/4HANA data without custom ETL layers.
A utility company implements MDG for 2.3M customer master records, reducing Joule response errors by 60% and enabling SAC predictive analytics without custom ETL transformations.
- Custom Z-fields and non-standard structures blocking AI model training and Joule accuracy
- Multiple conflicting golden records for the same customer or material across systems
- No data ownership model — data quality is nobody's accountability
- Implement SAP Master Data Governance (MDG) for customer, material, and supplier master data
- Use Custom Fields (YY1_ prefix) instead of Z-table extensions for business-specific attributes
- Align the data model to SAP's semantic layer to enable Business Data Cloud readiness
Integration Clean Core replaces point-to-point, database-level, and RFC/BAPI-based integrations with released OData V4 APIs, SOAP APIs, and Business Events consumed via SAP Integration Suite and SAP Event Mesh.
100% of new integrations use released SAP APIs. Legacy integrations are progressively migrated to Integration Suite-managed flows. No direct database access from external systems.
A financial institution replaces 180 custom RFC calls to S/4HANA Finance with 23 released OData V4 APIs via Integration Suite, reducing integration maintenance by 70% and enabling full upgrade automation.
- Direct DB table access breaking on every upgrade — SELECT on SAP tables is not an integration contract
- Hundreds of custom RFCs that bypass SAP business logic, authorisations, and audit trail
- Point-to-point connections creating spaghetti architecture impossible to govern or monitor
- Adopt Integration Suite as the central integration hub — prohibit direct system-to-system connections
- Replace custom RFCs/BAPIs with released OData V4 APIs catalogued on api.sap.com
- Implement Event Mesh for asynchronous, event-driven integration patterns
Extension Clean Core enforces a strict development hierarchy: Key User Extensibility first, then Developer Extensibility (ABAP Cloud), then Side-by-Side extensions on BTP. Direct modification of SAP standard objects is prohibited.
All active custom code is ABAP Cloud compliant. New developments follow the extension hierarchy. Legacy custom code is systematically analysed, classified, and remediated.
An energy company analyses 8,200 custom programs with CCA, finds 40% are never executed, removes 3,300 objects, and migrates remaining 1,800 to ABAP Cloud — achieving 90%+ ATC compliance.
- 10,000+ custom Z-programs using deprecated APIs that block every S/4HANA upgrade
- Custom code that directly modifies SAP standard tables or bypasses standard business logic
- No systematic analysis of which custom code is actively used versus dead code
- Execute SAP Custom Code Analysis (CCA) to identify usage frequency and upgrade impact
- Enforce ABAP Cloud compliance for all new developments via ABAP Test Cockpit (ATC) in CI/CD
- Follow the 5-level extension hierarchy — document every deviation with business justification
Operational Clean Core establishes the processes, tooling, and governance for continuous innovation — automated testing, CI/CD pipelines, release governance, and proactive upgrade readiness monitoring via SAP Cloud ALM.
Upgrade lead time reduced from 18+ months to 3–6 months. Automated regression testing covers all critical business processes. Cloud ALM provides real-time operational visibility.
A retail group implements Cloud ALM with 2,400 automated test cases, reducing upgrade validation from 9 months of manual testing to a 3-week automated validation cycle.
- Annual upgrades take 12–24 months due to extensive manual regression testing requirements
- No automated test coverage — every release requires costly and slow manual validation
- Reactive monitoring: issues discovered by business users long after they occur
- Implement SAP Cloud ALM for Application Lifecycle Management, monitoring, and upgrade planning
- Build automated test suites using Cloud ALM Test Automation aligned to clean core processes
- Establish a Continuous Upgrade Readiness programme with quarterly health checks
Process Clean Core
Fit-to-Standard as the strategic default. Every process exception is a liability — not a competitive advantage.
SAP Signavio — Process Governance Platform
SAP Signavio is the recommended platform for process intelligence, process mining, and business process management in clean core implementations. It provides three capabilities critical to Process Clean Core:
Mining actual execution data from S/4HANA to reveal how processes really run versus how they are documented. Identifies variants, deviations, and automation opportunities at scale.
Compares current process footprint against SAP Best Practices to quantify the gap. Produces a scored assessment showing which processes are good candidates for standardisation.
Lifecycle management for business processes — ownership, approval workflows, compliance tracking, and change documentation. Prevents uncontrolled process variance from re-emerging post-migration.
Data Clean Core
Master Data Governance as strategic infrastructure. The quality of enterprise AI depends entirely on the quality of enterprise data.
SAP Master Data Governance (MDG)
MDG is the SAP standard platform for governing master data across Customer, Supplier, Material, Finance, and Business Partner domains. It provides central governance, workflow-driven change management, data quality enforcement, and multi-system replication — all within the S/4HANA platform.
Data Quality Management
Data Clean Core requires published, measurable data quality SLAs per master data entity. Completeness, accuracy, consistency, and timeliness must be tracked. SAP MDG provides data quality dashboards and KPI scoring integrated with the Clean Core compliance view in Cloud ALM.
Data Ownership Model
Every master data entity requires a designated Business Data Owner accountable for its quality and lifecycle. IT cannot own business data. The Data Stewardship Council governs cross-entity consistency. This is a business governance decision, not a technology configuration.
Business Data Cloud Alignment
Business Data Cloud (BDC) unifies SAP and non-SAP data into a governed semantic layer for AI and analytics. Clean data architecture — standard SAP data models, no Z-table proliferation, MDG-governed master data — is the prerequisite for BDC to deliver value without expensive transformation layers.
Why AI Depends on Data Clean Core
Joule retrieves live data from S/4HANA via OData V4 APIs. Inconsistent or incomplete master data directly degrades response quality. A customer record with 3 conflicting names returns ambiguous, unreliable answers.
Retrieval-Augmented Generation in Gen AI Hub grounds LLM responses in enterprise data via HANA Vector Engine. Semantically inconsistent data produces poor embedding quality and irrelevant retrieval results.
SAC Smart Insights and predictive planning models are only as reliable as the data they consume. MDG-governed, harmonised data enables trustworthy AI-generated analytics narratives and forecasts.
Integration Clean Core
API-first and event-driven architecture as enterprise standards. Replacing direct database access and custom RFCs with released integration contracts.
Legacy Integration vs Clean Core Integration — Dimension-by-Dimension Comparison
Dimension | Legacy IntegrationPoint-to-point / RFC / Direct DB | Clean Core IntegrationReleased APIs / Event MeshGenerally Available |
|---|---|---|
| Architecture Pattern | ||
| Primary style | Point-to-point, custom RFCs, BAPI calls | API-first via Integration Suite and Event Mesh |
| Data access method | Direct SELECT on SAP tables | Released OData V4 APIs only — catalogued on api.sap.com |
| Coupling model | Tightly coupled — version-specific bindings | Loosely coupled — stable C1 API contracts |
| Upgrade Behaviour | ||
| Upgrade impact | Every upgrade may break all integrations | Released API contracts guarantee backwards compatibility |
| Regression testing | Full manual re-test of all integrations | API versioning manages changes; automated testing viable |
| Governance and Security | ||
| Security model | Custom auth — frequently bypasses SAP authorisations | Standard auth objects + Principal Propagation via BTP |
| Observability | No central monitoring — errors go undetected | Integration Suite monitoring dashboard with alerting |
| Documentation | Informal or undocumented — tribal knowledge | api.sap.com catalogue with machine-readable OpenAPI specs |
| Event Architecture | ||
| Event patterns | Custom RFC-based callbacks, polling | Released Business Events via SAP Event Mesh |
| Async decoupling | Custom queue implementations, high risk | Event Mesh with guaranteed delivery and dead-letter queues |
SAP Integration Suite as the Hub
SAP Integration Suite replaces point-to-point connections with a governed integration hub providing Cloud Integration (iFlow-based), API Management, Event Mesh, and Trading Partner Management — all with central monitoring.
- Central API catalogue — all integrations visible and governed
- Pre-built integration content from SAP Integration Content Catalogue
- API versioning — breaking changes managed gracefully
- OAuth 2.0 and Principal Propagation for secure, audited access
SAP Event Mesh — Event-Driven Architecture
SAP Event Mesh enables asynchronous, event-driven integration using released S/4HANA Business Events — published automatically without polling or custom change-pointer programmes.
- Released Business Events from api.sap.com/events — upgrade-safe contracts
- CloudEvents specification for interoperability with any consumer
- Guaranteed delivery with dead-letter queue management
- Enables real-time integration without tight coupling
Extension Clean Core
SAP's five-level extension hierarchy — from configuration to last resort. Every business requirement has a clean core path.
The most common outcome of a proper fit-to-standard analysis: SAP standard functionality already meets the requirement. No development needed — only configuration.
Business power users extend SAP without ABAP development. Custom fields, adapted UI layouts, business rules, and process variants — all upgrade-safe and managed via Fiori apps.
ABAP Cloud developers extend S/4HANA using SAP-released (C1) extension points. All code compiles against ABAP Cloud restrictions — guaranteeing upgrade safety. This is the boundary of in-system ABAP development.
Complex business innovations benefiting from cloud-native architecture, microservices, or low-code approaches are built outside S/4HANA on BTP — connected via released OData V4 APIs and Principal Propagation.
Legacy-mode ABAP using deprecated APIs, direct table access, or modifications. Only permitted in on-premise landscapes with explicit Architecture Review Board exception approval. Not available in RISE/GROW environments.
Operational Clean Core
The governance, release management, and lifecycle disciplines that make clean core sustainable — not just a one-time cleanup.
SAP Cloud ALM
SAP Cloud ALM is the recommended Application Lifecycle Management platform for cloud-oriented SAP landscapes. For clean core, it serves as the control tower — surfacing ATC violations, integration anomalies, and process deviations across all connected systems in a single compliance dashboard.
Release Management
Operational Clean Core requires a structured Release Management process: a quarterly release calendar aligned to SAP's cadence, defined freeze periods, automated regression test execution, and UAT sign-off gating. The target is consuming each SAP release within 90 days of its general availability.
Upgrade Readiness
Continuous Upgrade Readiness is not a project — it is an operational posture. SAP Cloud ALM provides an Upgrade Readiness dashboard monitoring custom code ATC status, active SAP Notes, deprecated API usage, and test automation coverage. Clean core organisations run this review quarterly.
Technical Debt Control
Once achieved, clean core compliance must be maintained. Technical debt gates in the CI/CD pipeline (ATC checks, API contract validation, integration compliance scanning) prevent new debt from entering the landscape. The ARB reviews and approves all exception requests.
Clean Core CI/CD Gate Checklist
Clean Core Maturity Model
Five levels from Legacy ERP to AI-Ready Enterprise. Use this model to assess current state, define target state, and communicate transformation progress to executive stakeholders.
The organisation operates with heavy customisations and no clean core awareness. Custom code proliferates unchecked, integrations use direct DB access, and every upgrade is a major multi-year project.
- Custom code >5,000 active objects with no usage analysis conducted
- No ABAP Cloud compliance policy — classic ABAP development continues unrestricted
- Direct DB access and RFC/BAPI-based integrations predominate
- Upgrade cycle >24 months; last upgrade more than 3 years ago
- No Master Data Governance — multiple conflicting master data sources
Clean core awareness exists at the architecture level. Some new developments follow ABAP Cloud. Integration Suite is in use for new integrations but legacy point-to-point connections remain.
- Custom Code Analysis (CCA) executed — results documented but remediation not yet started
- ABAP Cloud applied to new developments, but existing legacy code unremediated
- Integration Suite deployed for select integrations alongside legacy connections
- SAP Best Practices evaluated but process variance remains high
- Cloud ALM deployed but manually operated with limited automation coverage
Clean core governance is formalised and actively enforced. All new developments must pass ABAP Cloud ATC checks. Integration Suite is mandated for all new integrations. Legacy remediation programmes are underway.
- Architecture Review Board (ARB) reviews all custom developments before approval
- ATC clean core checks enforced in CI/CD pipeline — no exceptions without ARB approval
- Integration Suite mandated for all new integrations; legacy migration roadmap in place
- MDG deployed for at least two master data entities
- Upgrade readiness health checks executed quarterly via Cloud ALM
Clean core is a strategic enterprise discipline. Legacy custom code remediation is largely complete. The organisation adopts SAP innovations within the release cycle. AI adoption is accelerating.
- Custom code reduced by ≥70% from baseline; remaining code 100% ABAP Cloud compliant
- All integrations via Integration Suite using released APIs — no legacy point-to-point
- MDG deployed across all critical master data domains; BDC alignment in progress
- Upgrade lead time ≤6 months with ≥80% automated test coverage
- Joule deployed and actively used; at least one AI use case live in production
The organisation operates a fully clean core. AI is deeply embedded in business processes via Joule, Agentic AI, and SAP Business AI. Innovation is continuous — new SAP capabilities adopted within quarters.
- Zero non-compliant custom code — full ABAP Cloud purity across the landscape
- Business Data Cloud deployed — unified semantic layer for all AI and analytics workloads
- Joule broadly deployed across Finance, HR, and Procurement with measurable productivity gains
- Agentic AI pilots active; formal AI Governance framework operational
- Upgrade lead time ≤3 months; active participation in SAP Early Adopter Care programmes
Clean Core Maturity Assessment Scorecard — Dimension View
Dimension | Level 1Legacy ERP | Level 2Partial Align | Level 3Managed | Level 4Strategic | Level 5AI-ReadyGenerally Available |
|---|---|---|---|---|---|
| Process | Uncontrolled variance | Best Practices evaluated | Standard baseline adopted | Signavio-governed | AI-optimised processes |
| Data | Siloed, inconsistent | MDG piloted | MDG active, quality SLAs | Single source of truth | BDC semantic layer live |
| Integration | Direct DB, custom RFCs | Some API usage | API-first policy in place | Event-driven, loosely coupled | Full Event Mesh adoption |
| Extension | Classic ABAP, direct mods | Mixed — some ABAP Cloud | New dev: ABAP Cloud only | Full ATC enforcement + gating | Side-by-side first + AI |
| Operations | Manual, reactive | Basic monitoring | Cloud ALM integrated | Continuous delivery | AI-driven operations |
Clean Core and SAP BTP
Why SAP positions Business Technology Platform as the innovation layer — and how S/4HANA clean core makes BTP adoption seamless and sustainable.
CAP — Cloud Application Programming Model
CAP is SAP's preferred framework for side-by-side extensions on BTP. Node.js and Java runtimes, OData V4 by default, HANA Cloud persistence, and declarative CDS data modelling. Clean core mandates CAP as the first choice for complex business logic outside S/4HANA.
SAP Build — Low-Code Platform Suite
SAP Build comprises Build Apps (visual low-code applications), Build Process Automation (workflow + RPA), and Build Work Zone (digital workplace). It enables business technologists to build extensions without ABAP — extending SAP without touching the core.
SAP Build Work Zone
Work Zone is the unified digital workplace aggregating Fiori apps, BTP applications, third-party apps, and Joule into a single launchpad. It is the recommended entry point for all business user interactions with SAP in a clean core landscape.
Integration Suite
Integration Suite is the BTP service managing all integrations between S/4HANA and third-party systems. In a clean core architecture, Integration Suite is the only permitted integration pathway — no direct system-to-system connections.
AI Core and Gen AI Hub
SAP AI Core (MLOps platform) and Gen AI Hub (20+ foundation models) are BTP services that depend on clean core for their S/4HANA integrations. Joule uses released OData V4 APIs via Principal Propagation — clean core is Joule's structural prerequisite.
Clean Core and SAP Business AI
Clean Core is not just an upgrade strategy — it is the foundational prerequisite for SAP Business AI, Joule, Agentic AI, and the Business Data Cloud.
Joule Requires Clean APIs
SAP Joule uses only released OData V4 APIs to interact with S/4HANA business objects. If custom business logic lives in Z-programmes unreachable via released APIs, Joule cannot access or orchestrate it. Clean core is a structural prerequisite — not an optional enhancement.
Agentic AI Requires Released Actions
SAP Joule Agents and the SAP Agent Builder use Tool Use patterns — calling OData V4 actions, BPA workflows, and HANA Vector search as tools. Every tool must be a released API. Custom RFCs and Z-function modules cannot be agent tools by design.
Business Data Cloud Requires Clean Data
Business Data Cloud provides the unified semantic layer for AI and analytics. It ingests data from S/4HANA using standard data models and SAP Datasphere. Non-standard Z-tables and inconsistent master data require expensive transformation layers that undermine BDC's value proposition.
Standardised Processes Improve AI Accuracy
SAP Business AI models are trained on standard SAP processes. When processes deviate significantly from standard, pre-built AI features produce inaccurate outputs. Fit-to-Standard process alignment — even to 70–80% — dramatically improves embedded AI capability accuracy.
Clean Core for On-Premise
Practical transformation roadmap for existing ECC and S/4HANA on-premise customers on the path to clean core compliance.
The On-Premise Reality
On-premise SAP customers — both ECC and S/4HANA — typically carry the heaviest clean core debt. Unlike RISE/PCE customers (where ABAP Cloud is enforced by SAP), on-premise customers have unrestricted access to all ABAP language features. This flexibility has historically been a licence to accumulate technical debt.
On-premise clean core is a voluntary discipline driven by business outcomes: lower TCO, faster future cloud migrations, and the ability to adopt SAP Business AI.
- Execute Custom Code Analysis (CCA) across all systems
- Map each custom object: business owner, usage frequency, upgrade risk
- Classify as: Eliminate / Migrate to BTP / Migrate to ABAP Cloud / Keep (justified)
- Enforce ABAP Cloud ATC checks for all new developments immediately
- Freeze all new Z-table creations without ARB approval
- Block new point-to-point integrations — mandate Integration Suite for all new connections
- Remove all custom objects with zero production usage (often 40–60% of the landscape)
- Archive or delete transport objects no longer in use
- Simplify before migration — less debt to carry forward reduces project risk
- Wave-by-wave migration of remaining objects to ABAP Cloud
- Replace highest-risk objects with BTP side-by-side alternatives using CAP
- Document every exception with business justification via ARB process
- Integrate ATC gates into CI/CD pipeline — no deployment without passing checks
- Monthly ARB review of technical debt metrics via Cloud ALM
- Quarterly Continuous Upgrade Readiness health check
Clean Core for Private Cloud (RISE with SAP)
RISE with SAP customers: Clean Core is mandatory, not optional. SAP manages your platform — ABAP Cloud compliance is contractually enforced.
SAP-Managed Upgrades
SAP manages and executes annual upgrades for RISE customers. Clean core compliance ensures these upgrades succeed without customer-side remediation. Customers with non-compliant custom code face upgrade delays and potential supportability issues.
Custom Code Reduction Strategy
RISE new-build customers: start from SAP Best Practices with zero custom code tolerance. RISE brownfield migrations: execute CCA pre-migration, eliminate unused code, migrate remainder to ABAP Cloud before go-live. Post-go-live: ATC enforcement from day one.
Pre-Migration Checklist
Before migrating to RISE: complete CCA, achieve 80%+ ABAP Cloud compliance, migrate top-10 integrations to released APIs, deploy MDG for critical master data, establish ARB governance. These preparation activities determine migration complexity and timeline.
Private Link and Connectivity
RISE with SAP uses SAP Private Link Service (Azure/AWS) for secure BTP connectivity. Clean core integration architecture — using Destination Service, Integration Suite, and Principal Propagation — is the reference architecture for all RISE-to-BTP connections.
Clean Core for Public Cloud (GROW with SAP)
S/4HANA Public Cloud Edition — Fit-to-Standard is the only viable implementation strategy. Extensibility is bounded by architecture.
Fit-to-Standard is Mandatory
Public cloud quarterly upgrade cadence means customised processes cannot survive. The implementation methodology is: adopt SAP standard, configure within the provided options, use Key User tools for necessary adaptations. Any requirement that cannot be met this way must be re-evaluated as a business process redesign challenge.
Key User Extensibility Only
Extensibility in public cloud is limited to: Custom Fields (YY1_), Custom Business Objects, Adaptation UI Editor, Business Rules (BRF+), and Communication Arrangements for BTP integration. Developer-level ABAP extensibility is not available — it is a structural clean core guarantee, not a limitation.
Communication Arrangements to BTP
Complex requirements exceeding Key User extensibility scope are addressed via side-by-side extensions on BTP — connected through Communication Arrangements (OAuth 2.0) and released OData V4 APIs. This is the clean core pattern at its most architecturally disciplined.
Extensibility Scope by SAP S/4HANA Deployment Model
Extension Method | On-PremiseS/4HANA OP | RISE / PCEPrivate CloudGenerally Available | GROW / PublicPublic CloudGenerally Available |
|---|---|---|---|
| In-System Extensibility | |||
| Key User Extensibility (Custom Fields, BRF+, UI Adaptation) | |||
| Developer Extensibility — ABAP Cloud (BAdIs, RAP, CDS) | |||
| Classic ABAP — Modifications (non-ABAP Cloud) | ARB exception | ||
| Side-by-Side Extensibility (SAP BTP) | |||
| CAP Applications on Cloud Foundry / Kyma | |||
| SAP Build Apps and Build Process Automation | |||
| SAP Build Work Zone | |||
| Joule Studio — Custom Skills | Planned | ||
| Integration | |||
| Released OData V4 APIs via Integration Suite | |||
| Communication Arrangements (BTP integration) | |||
Clean Core Governance
The enterprise governance model that makes Clean Core a sustained organisational capability — not a one-time cleanup project.
Architecture Review Board (ARB)
The ARB is the cross-functional governance body that owns the clean core mandate. Recommended membership: CTO/SAP CoE Lead (chair), Enterprise Architect, Lead ABAP Architect, Integration Architect, Data Architect, and Business Process Lead. The ARB reviews all exception requests and defines architecture standards.
API Governance
The API Governance pillar maintains the enterprise API catalogue, enforces API-first design standards, manages API versioning and deprecation policy, and monitors integration compliance. It owns the api.sap.com released API register and ensures no undocumented API usage enters the landscape.
Extension Governance
Extension Governance enforces the extension hierarchy through ATC pipeline gates, reviews all ARB exception requests for Classic ABAP usage, monitors the ATC compliance score trend, and manages the Custom Code Remediation backlog. It owns the Clean Core compliance dashboard in Cloud ALM.
Data Governance
The Data Stewardship Council owns master data quality SLAs, appoints Business Data Owners per entity, governs MDG workflow and approval processes, and measures data quality scores. It aligns the enterprise data model with SAP's semantic layer for Business Data Cloud readiness.
AI Governance
The AI Governance Council defines responsible AI policies, approves new AI use cases, monitors model behaviour and bias, manages data privacy compliance for AI features (LLM grounding, RAG), and governs Agentic AI permission boundaries. AI governance is a clean core requirement from the moment AI enters the landscape.
Business Value of Clean Core
Executive summary — the quantifiable business outcomes that justify Clean Core investment and sustain executive sponsorship.
75% faster
Clean core organisations adopt new SAP innovations within the release cycle. Non-clean core requires multi-year remediation before each upgrade.
3–6 months
Automated testing, ABAP Cloud compliance, and API-based integrations reduce upgrade lead time by 75–85%.
Up to 50%
Elimination of custom code maintenance, reduced testing effort, and cloud-native operations directly reduce ERP operating cost.
100%
Clean core organisations consume all SAP Business AI features — including Joule skills, embedded AI, and Agentic AI — without bespoke integration work.
60% less
CCA-driven elimination typically removes 40–60% of custom objects. Remaining ABAP Cloud objects require dramatically less ongoing maintenance effort.
Quarterly
Target state: consume each SAP release within 90 days of GA. Clean core makes this operationally achievable — a strategic advantage over slower competitors.
Executive KPI Dashboard
- Custom Code Compliance (ABAP Cloud ATC)
- Target: ≥90% — track monthly via Cloud ALM
- Integration Compliance
- Target: 100% new integrations via released APIs
- Master Data Quality Score
- Target: ≥95% across all MDG-governed entities
- Process Standardisation Rate
- Target: ≥80% standard process adoption (Signavio)
- Upgrade Lead Time
- Target: ≤6 months Year 2, ≤3 months Year 3+
- Test Automation Coverage
- Target: ≥80% of critical business scenarios
- AI Feature Adoption Rate
- Target: Joule active users + measurable productivity KPI
- Clean Core Maturity Level
- Target: Level 4 by Year 3, Level 5 by Year 4
SAP Sapphire Clean Core Guidance
SAP's latest clean core announcements, tools, and roadmap items. Status clearly distinguished: Generally Available · Planned · Roadmap · Future Direction.
The restricted ABAP language version enforcing clean core compliance at compile time. Available in all S/4HANA 2022+ releases and enforced via the ABAP Test Cockpit (ATC).
Tool to analyse all custom ABAP programmes for usage frequency, upgrade risk, and API compliance. Available in SAP Maintenance Planner and directly within S/4HANA systems.
Real-time clean core compliance scoring across Extension, Integration, and Process dimensions visible in SAP Cloud ALM for all connected S/4HANA systems.
SAP's official C0/C1/C2 extensibility classification enforced at compile time, defining stable (C1) extension contracts from internal-use-only (C0) objects.
Authoritative catalogue of all released (C1) APIs, BAdIs, and Business Events available for clean core extensions — the official developer contract reference.
Automated analysis of integration interfaces to identify non-clean-core patterns (direct DB access, custom RFCs) and recommend migration paths to released API alternatives.
SAP plans to embed generative AI into the Custom Code Analysis report to automatically recommend clean core migration strategies per individual code object.
A consolidated clean core health score across all five dimensions to be surfaced in the SAP for Me customer portal, providing executive-level visibility.
SAP plans direct integration between Master Data Governance and Business Data Cloud for seamless master data harmonisation supporting AI and analytics use cases.
SAP has shared a roadmap direction for Joule to provide natural-language guidance on upgrade readiness, custom code remediation priorities, and SAP Note application.
SAP Signavio process mining capabilities are on the roadmap to be more deeply integrated with S/4HANA migration tooling to automate fit-to-standard gap identification.
SAP has indicated a direction for AI to generate regression test cases based on custom code and process analysis, reducing manual test creation effort significantly.
SAP's long-term vision: AI autonomously prepares and validates upgrade readiness with minimal human intervention, leveraging clean core discipline as the foundational enabler.
SAP has indicated exploration of AI agents capable of automatically refactoring legacy ABAP code to ABAP Cloud compliance, with structured human review and approval gates.
The Clean Core Transformation Playbook
Four-year enterprise transformation roadmap — from assessment to AI-driven enterprise. Quarterly milestones, measurable outcomes, and actionable steps.
Critical Success Factors
Core compliance rules and the C0/C1/C2 extensibility model
Decision guide: which extension method for which requirement
ABAP Cloud patterns — CDS, RAP, BAdI implementations
No-code — Custom Fields, UI Adaptation, Business Rules
BTP extensions via released OData V4 APIs and CAP
Tier 2 in-system — BAdIs, Custom Fields, Custom BOs
Restricted language version — what's blocked, what replaces it
OData V4 services, CDS data models, Behaviour Definitions
Business Add-Ins — C1 released extension points with examples
Pre-upgrade checklist, API deprecation, CI/CD pipeline
RISE with SAP — ABAP Cloud mandatory, managed upgrades
GROW with SAP — Key User only, quarterly upgrades
ECC/S4 on-premise — ABAP modernisation journey
SAP Activate methodology and Clean Core workstream
YY1_ field extensions, OData exposure, Business Contexts