The S/4HANA migration market is driven by a powerful combination of the 2027 deadline pressure and aggressive SAP and partner marketing. While S/4HANA offers genuine benefits, the path to realizing them is often more complex than presentations suggest. Understanding these myths can save your organization significant time, money, and frustration.
Myth 1: A system conversion is faster and cheaper than reimplementation
The Myth
Brownfield (system conversion) is always the quick, low-cost path to S/4HANA.
The Reality
While brownfield conversions can be quicker for simple landscapes, complex organizations with significant customization often find conversions take 18-24 months with costs rivaling greenfield. The hidden complexity in custom code remediation, interface updates, and testing often surprises organizations.
Business Impact
Organizations underestimate effort by 40-60%, leading to budget overruns and timeline extensions.
Myth 2: SAP handles everything in RISE
The Myth
RISE with SAP is fully managed - just sign and SAP takes care of the rest.
The Reality
RISE is a shared responsibility model. While SAP manages infrastructure and some technical operations, your team remains responsible for:
- Application management and configuration
- Security policies and access control
- Integration maintenance
- Testing and validation
- Business process optimization
Many customers discover these gaps only after go-live.
Business Impact
Understaffed project teams and unexpected operational responsibilities post go-live.
Myth 3: You can migrate your custom code as-is
The Myth
Our ABAP code will work fine in S/4HANA with minimal changes.
The Reality
S/4HANA requires significant custom code changes. Approximately 30-40% of custom code won't function without modification due to:
- Database changes (anyDB to HANA)
- Deprecated objects and function modules
- New data models (Business Partner, Material Ledger)
- Changed table structures
The Custom Code Migration App reveals the true scope - run it early.
Business Impact
Projects stall in conversion phase as the volume of required code changes becomes apparent.
Myth 4: 12-18 months is a realistic timeline for large enterprises
The Myth
We can complete our S/4HANA migration in 12-18 months.
The Reality
For organizations with 5000+ users, significant customization, and complex integration landscapes, 24-36 months is more realistic. Fast implementations are possible but require scope trade-offs many organizations aren't prepared to make.
Business Impact
Compressed timelines lead to cut corners, inadequate testing, and post-go-live issues.
Myth 5: The 2027 deadline gives us plenty of time
The Myth
We have until December 2027 - there's no rush to start planning.
The Reality
With realistic 24-36 month timelines, organizations need to begin detailed planning in 2025 to safely make the deadline. Resource scarcity is already driving costs up as demand for experienced consultants exceeds supply.
Business Impact
Organizations waiting until 2026 face premium consulting rates and stretched partner resources.
Myth 6: S/4HANA delivers immediate business benefits
The Myth
We'll see ROI immediately after going live on S/4HANA.
The Reality
Out of the box, S/4HANA provides technical improvements but business value requires process redesign, user training, and often additional tools like analytics and automation. Many organizations see ROI timelines of 3-5 years.
Business Impact
Unrealistic ROI expectations create stakeholder disappointment and project criticism.
Myth 7: Partners can accurately estimate costs upfront
The Myth
The estimate from our SI is reliable and won't change much.
The Reality
Initial estimates are based on limited discovery. True costs emerge only after detailed analysis of custom code, integrations, data quality, and organizational change readiness.Fixed-price contracts often include extensive exclusions.
Business Impact
Budget surprises mid-project when scope is truly understood.
What Smart Organizations Do Instead
Conduct thorough discovery before committing
Invest in detailed custom code analysis, integration inventory, and data quality assessment before selecting an approach.
Build realistic timelines with contingency
Add 30-50% buffer to partner estimates. Assume the worst-case scenario for code remediation.
Understand the RISE shared responsibility model
Document exactly what SAP will handle vs. what remains your responsibility. Staff accordingly.
Set realistic ROI expectations
Focus on risk mitigation and technical currency as primary drivers. Business transformation ROI takes 3-5 years.
The Bottom Line
S/4HANA migration is a significant undertaking that requires clear-eyed planning. The organizations that succeed are those that resist pressure to compress timelines, invest in thorough discovery, and build realistic expectations with their stakeholders. Don't let myths drive your strategy - let data and experience guide you.
Frequently Asked Questions
How long does an S/4HANA migration really take?
Does SAP handle everything in RISE with SAP?
Can I migrate my SAP custom code to S/4HANA without changes?
When should we start planning for S/4HANA migration?
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Written by
Rick Porter
Founder, ERP Decision Office
With over two decades in the SAP ecosystem, Rick provides independent guidance to organizations navigating ECC continuity and S/4HANA transitions.
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