SAP Greenfield vs Brownfield Migration Assessment
The first big S/4HANA decision is how to get there. Greenfield starts clean, brownfield converts your existing system, and selective approaches mix the two. This assessment helps CIOs and program managers see which direction their situation favours before an expensive consulting workshop.
1. How satisfied are business users with how current processes are designed in ECC?
Satisfied users favour keeping process design (brownfield). Dissatisfied users favour redesign.
2. How heavily customised is your ECC system?
3. What is the quality of your master and transactional data?
4. Do you want to change the organisational or financial structure (chart of accounts, company codes, plants)?
5. How much historical data must remain in the new system?
6. How much business disruption can the organisation absorb?
7. How tight is your timeline and budget?
8. Are you consolidating multiple SAP systems or acquisitions into one?
9. How much do you want to adopt SAP best-practice content and new capabilities?
10. How well do you understand your current ECC configuration and documentation?
How to use the assessment
Answer the ten questions as honestly as you can, ideally with input from both IT and business owners. Each question measures one factor that influences the approach, from process satisfaction and customisation to data quality, structural change, history needs, disruption tolerance, timeline, consolidation, appetite for standard content and documentation quality. The total moves you along a scale from greenfield to brownfield. Treat the result as a hypothesis to validate, not as the final decision.
- Score with both IT and business input
- Use the result as a hypothesis
- Validate with a sandbox conversion
- Record the rationale for the steering committee
The three approaches in brief
Brownfield, or system conversion, upgrades the existing ECC system in place to S/4HANA, keeping configuration, history and custom code (subject to remediation). Greenfield implements a new S/4HANA system and migrates selected data, letting you redesign processes and adopt standard content. Selective data transition, sometimes called bluefield, uses specialist tooling to move chosen entities, companies or history into a new or converted system. Each has trade-offs in speed, disruption, cost and clean-up.
Interpreting the band
Low scores favour greenfield because the answers indicate redesign appetite, heavy customisation or poor data. High scores favour brownfield because change is unwelcome or time is short. The middle is where most real programs land, and where hybrid choices appear. Consider which answers drive your score: a single factor, such as a mandatory company restructure, can outweigh the rest and change the right approach.
Common mistakes
Teams often choose brownfield for speed, and then carry years of poor data and unused code into S/4HANA. Others choose greenfield for a clean slate but underestimate redesign, training and data migration effort. Another trap is deciding before knowing your custom code and data profile. Get the facts from Readiness Check and usage data first.
Frequently Asked Questions
Which approach is cheapest?
There is no universal answer. Brownfield often costs less in project effort for standard landscapes but may carry hidden clean-up costs. Greenfield can cost more upfront and lower the long-term cost of complexity. Compare with your own scope and use a sandbox to firm up estimates.
Can I move to S/4HANA without disrupting users?
Brownfield tends to disrupt less in process terms, though the Fiori user experience, Business Partner and finance changes still affect people. Plan training and communication for every approach.
What is selective data transition?
It is an approach using specialised tools and services to migrate chosen parts of an existing system, such as one company code or recent history, into S/4HANA. It suits carve-outs, mergers and cases where neither pure option fits.
Does the choice affect RISE?
Not directly. RISE is a commercial and operating model, not a migration approach. You can use any of the approaches with RISE or with other hosting options, although some details of the technical path depend on the target environment.
If you want to test your result against your own landscape, we can review your analysis with you and discuss tooling. The assessment is complete without us.
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