Across Germany, hundreds of companies are currently assessing how and when to migrate from SAP ECC to SAP S/4HANA. With the official support for ECC ending in 2027, pressure is growing — but rushing into migration without structure is a risk.
At principal33, we support German businesses across sectors like energy, manufacturing, and technology in planning and executing strategic, phased SAP S/4HANA migrations with minimal disruption and long-term value.
In this post, we break down the six essential phases of a well-planned migration. It’s not a technical guide — it’s a roadmap for business and IT decision-makers who need control, visibility, and confidence.
Phase 1: System assessment and current-state analysis
Every migration starts with a clear understanding of where you are. That includes:
- Existing SAP version and system architecture
- Active modules and business-critical customizations
- Data volume and quality
- Interfaces and legacy systems
- Infrastructure and performance bottlenecks
In Germany, many companies operate heavily customized SAP ECC systems built over years. That’s why it’s crucial to assess which processes should be kept, reworked, or eliminated — and to choose the right migration strategy:
- Greenfield (new implementation)
- Brownfield (system conversion)
- Selective Data Transition (flexible hybrid approach)
Phase 2: Goal definition and strategic planning
Once the analysis is complete, it’s time to align business and IT. This phase involves:
- Setting business goals for the project
- Defining KPIs (e.g. process efficiency, automation rates, data quality)
- Identifying phase scope and prioritizing critical areas
- Estimating available resources and internal capabilities
- Outlining a realistic timeline and milestones
In the German market, it’s also essential to evaluate whether a cloud model (e.g. RISE with SAP) or On-Premise deployment fits your compliance and infrastructure environment.
Phase 3: Target solution design (To-Be)
This is the blueprint of your future SAP system:
- Review of standard vs. custom processes
- Mapping of workflows, business rules, and user roles
- System architecture and integration design
- Functional improvements compared to the current setup
- Consideration of add-ons like SAP C4U or SAP BTP
German companies often balance cost-saving through standardization with the need for tailored functionality — this phase ensures business-critical processes are preserved, not compromised.
Phase 4: Data and infrastructure preparation
This is where complexity grows. Tasks include:
- Cleaning and validating legacy data
- Preparing the data model and migration rules
- Setting up development, test, and production environments
- Establishing cloud or on-premise infrastructure
- Testing system compatibility and connectivity
For German utilities and regulated industries, data traceability, auditability, and integrity are non-negotiable.
Phase 5: Technical build and testing
Now the project comes to life:
- Performing technical migration or full installation
- Configuring SAP S/4HANA for target processes
- Developing required customizations
- Running unit, integration, and end-user testing
- Training key users by department and function
In many German implementations, agile delivery with functional sprints proves most effective — allowing teams to validate results by module or department.
Phase 6: Go-Live and stabilization
This is where value is delivered — and risks must be tightly controlled:
- Executing go-live in full or phased rollout
- Ensuring real-time support during cutover
- Monitoring performance of live processes
- Logging and resolving incidents quickly
- Reviewing feedback and applying optimizations
A structured post-go-live plan is essential: performance monitoring, KPI tracking, and user feedback loops ensure that the migration delivers measurable value.
Conclusion
Planning your SAP S/4HANA migration in six strategic phases gives you more than order — it provides resilience, predictability, and business alignment.
At principal33, we help German companies approach this journey with confidence. Whether you are just getting started or looking for an experienced partner to execute your roadmap, we offer end-to-end guidance that combines technical depth with local understanding.
If you’re preparing to migrate to S/4HANA, contact us. A well-structured plan is the difference between disruption and transformation.
