The biggest decision in an S/4HANA project is the transition path. It affects timeline, budget, risk and how much your processes change.
Greenfield (new implementation)
You start with a new S/4HANA system, use SAP best-practice processes and migrate only the master data and open items you need.
Choose it when
- Processes are outdated or heavily customised
- The organisation has changed (mergers, new business models)
- You want to adopt standard processes and a "clean core"
Trade-offs: more process change, more training, historical data stays in the old system or an archive.
Brownfield (system conversion)
Your existing ECC system is technically converted to S/4HANA, keeping configuration, custom code and history.
Choose it when
- Processes work well and should remain
- Historical data must stay in the system
- You want a faster technical migration and plan process innovation later
Trade-offs: existing complexity and technical debt come along; custom code must be adapted.
Selective data transition
A new S/4HANA system is built, and selected data (for example certain company codes or years) and configuration are transferred with specialised tools.
Choose it when
- You want to redesign some areas but keep others
- Carve-outs or consolidation of several systems are needed
Trade-offs: requires specialised tools and expertise.
Comparison
| Criteria | Greenfield | Brownfield | Selective |
|---|---|---|---|
| Process redesign | High | Low | Medium |
| History in system | No | Yes | Selected |
| Custom code | Rebuilt as needed | Adapted | Selected |
| Change management | High | Lower | Medium |
| Flexibility | High | Lower | High |
How to decide
Analyse your system (Readiness Check), custom code, data quality, business strategy and appetite for change. Often a workshop with key users and IT makes the decision clear.
We help you evaluate the options objectively and plan the path that fits your business.