People, culture and communication — S/4HANA migration

Beyond the Hype: 5 Surprising Truths about the SAP S/4HANA Migration

The 2027 countdown is on — what really matters

Many treat S/4HANA as an IT upgrade. In reality, it's a business transformation. Here are the five truths that decide success — and how you implement them.

Why projects derail

The upcoming end of support for SAP ECC by 2027 creates pressure. The biggest barriers are rarely technical: process changes, custom code complexity, and organizational resistance dominate. Treating a transformation as a simple upgrade leads to blown budgets and timelines.

49%
Process changes
44%
Customizations
37%
Org resistance
“More cultural transformation than checklist — technology is rarely the main problem.”

Carrying legacy processes into a modern system limits value. Your willingness to redesign how you work is the true success factor.

The 5 surprising truths

1. People and processes beat technology

Success depends on governance, ownership, and change capability. Empower process owners, clarify roles, and eliminate shadow IT via an approved API catalog.

2. Your custom code is a time bomb

Refactor, don't carry. Run ATC against the Simplification Database, prioritize findings, and apply Quick Fixes. 70–80% of tasks can be automated.

3. Hybrid beats dogma

Selective Data Transition (Bluefield) blends targeted redesign (Greenfield) with efficient carry-over (Brownfield) — modernize where it matters.

4. Testing decides the go-live

Automated regression, end-to-end, data reconciliation, and performance testing shorten cycles and protect core processes.

5. The goal is a Clean Core

Keep the ERP core close to standard and build extensions side-by-side on BTP. This reduces TCO, keeps updates predictable, and enables reliable AI (e.g., Joule).

The pragmatic path

Adopt a hybrid migration with strict automation and governance. Combine SDT with custom code remediation, robust test automation, and Clean Core discipline.

Building blocks

  • ATC/Quick Fixes: automate violation fixes
  • SDT: redesign or carry over by business value
  • Test automation: regression, E2E, reconciliation, performance
  • Clean Core: ABAP Cloud, approved APIs/events, side-by-side

Outcome: lower risk, predictable quality, faster time to value.

Impact for the European market

Compliance-by-design with GDPR and the EU AI Act, EU data residency, auditability, and centralized identity — achievable with BTP services and Clean Core policies.

GDPR
Data minimization & roles
EU AI
Risk management & oversight
BTP
Identity & observability

Regulation & governance

Technical enablers

  • Integration Suite as secure API hub
  • Generative AI Hub with grounding & logging
  • Cloud Identity Services for provisioning & SSO
  • Approved, versioned sources for RAG
“AI needs standardized processes and harmonized master data to work reliably.”

What you get

A structured path from baseline to go-live — with measurable quality and clear ownership.

Code remediation

ATC, Quick Fixes, ABAP Cloud guidelines.

SDT design

Selective carry-over and targeted redesign.

Test automation

Regression, E2E, data reconciliation, performance.

Clean Core governance

APIs/events, identity, observability.

Your benefits

Lower risk, higher quality, faster value realization.

-60%
Remediation cost (automation)
x10
faster test cycles
Clean
Core reduces TCO
EU
Compliance confidence

Practical examples

Battle-tested patterns across domains.

Order-to-Cash

E2E tests incl. third-party systems, automated validation.

Custom code

Mass fixes via Quick Fixes, remaining edge cases by guidelines.

SDT

Selective carry-over with lower go-live risk.

Clean Core

ABAP Cloud & side-by-side for upgrade-safe extensions.

Challenges

Manual testing, legacy dependencies, data consistency, and change management are the main risks — all addressable via automation and governance.

Testing

Automate regression, E2E, load/performance.

Data

Automated reconciliation of legacy vs. S/4HANA.

Legacy

Identify and fix custom code risks early.

Change

Activate process owners and clarify roles/permissions.

Roadmap in 4 steps

From foundation to value delivery.

1 — Assessment

Current processes, custom code, integrations, test maturity.

2 — Hybrid design (SDT)

Define target processes; carry-over vs. redesign by value.

3 — Automate

ATC/Quick Fixes, test suites, reconciliation, CI/CD.

4 — Secure go-live

Performance tests, cutover plan, observability, hypercare.

Success factors

  • Standardize before you automate
  • Transparent API catalog with approvals
  • KPIs for quality, time, and cost
  • Strict Clean Core policy

Why it matters strategically

The migration is more than a system switch. It builds the foundation for an AI-ready, agile enterprise with a reliable core and clear governance.

Agility

Faster updates, less tech debt.

Trust

Auditable AI actions and data flows.

Value

Measurable improvements in core processes.

“Clean Core + automation + SDT = predictable S/4HANA value.”

Conclusion

Treat S/4HANA as an organizational and process program. Automate custom code remediation and testing, choose a hybrid path, and anchor a Clean Core — delivering real, AI-ready value by 2027 and beyond.

Takeaways

  • People and processes first — technology follows
  • ATC/Quick Fixes + SDT = less risk, more speed
  • Test automation is your insurance policy
  • Clean Core is the strategic end state

Further reading

FAQ

Do we need special tools for SDT? +
Partner solutions accelerate extraction and transformation. Your target architecture and governance remain the decisive factors.
How do we prioritize custom code fixes? +
Sort ATC findings by criticality and process relevance; address mass fixes first, then edge cases.
Which tests bring the highest value? +
Regression for standard and custom code, E2E for core processes, data reconciliation for financial accuracy, performance for go-live stability.
Is on-prem still viable? +
Yes. Cloud-aligned principles (Clean Core, API hub, observability) still apply to ensure updatability and AI readiness.