Public cloud or greenfield? Know your own system first
Public cloud or private cloud? Greenfield or brownfield? Few questions are debated more passionately in the SAP world — and few so often on the wrong foundation. While target architectures are being argued over, most organizations cannot answer three simple questions about their current system.
And the rule holds: the quality of a target decision is bounded by the quality of the as-is picture it stands on.
The three questions that decide your target architecture
- What do you actually use? Not what is licensed or implemented — but which features actually produce documents in day-to-day business. The difference is regularly dramatic: a considerable share of what “must” be migrated is simply not used.
- How far are your processes from standard? The real processes from the document flows, that is — not the ones in the handbook. Some deviations are habits that can change; some are hard business requirements. For the cloud question, that distinction is exactly what matters.
- What do your custom developments do — and does anyone still need them? In a fit-to-standard model, every Z program is a potential hurdle. But only if it still runs at all. Unused custom code is not a migration problem, it is a retirement list.
What a sound documentation looks like
These questions define what the documentation has to deliver — connected, not as three separate lists:
- A feature layer that separates implemented from used, and standard from custom development.
- A process layer from the real document flows, with variants and volumes — so it becomes visible which deviation carries weight and which is a footnote.
- A custom code inventory that links every custom development to its usage and its business context.
The common thread is usage. Only usage turns inventories into decision material: whatever is not used neither has to fit the public cloud nor be carried into a greenfield.
From documentation to decision
With this picture, both target directions become concretely assessable — on the same factual basis, but with different questions:
Public cloud is a fit-to-standard model. The question is: how much of your real usage does the standard scope cover? That can be measured feature by feature — as a fit rate across the landscape and as a prioritized list of gaps, including the critical cases with no standard path.
Private cloud greenfield asks the reverse question: what do you deliberately take with you — and what do you leave behind? Here too, the as-is picture decides: processes with high volume and genuine differentiation earn a place in the target. Unused customization is not rebuilt, it is retired — the actual lever that keeps a greenfield “clean”.
The cloud edition is not the decision. The decision is what you take with you — and for that you have to know what you have.
Do this homework and the RISE-or-GROW debate suddenly gets much shorter: a system with a high fit rate and little genuine differentiation argues for the standard path. A system whose differentiation is demonstrably used and creates value justifies the larger degree of freedom. Neither remains a matter of belief.
This as-is picture is exactly what Conjola builds from your system’s real data: feature map and processes with actual usage, custom code with business context. Public Cloud Fit then matches that real usage against the scope item catalog of SAP S/4HANA Cloud Public Edition — as a fit rate per business area and a prioritized gap list. So the cloud question becomes an exercise in arithmetic, not a gut call.