What is a Clean Core Score, and how do you measure one?
One number to size a migration and track clean-core progress — from first scan to go-live.
The short answer
A Clean Core Score is a single 0–100 benchmark for how close an SAP estate is to a clean, standard core — the lower your reliance on custom code and modifications, the higher the score. It factors three things: the volume of custom objects, the age of your release, and how broadly customization spans your modules. It gives a CIO one honest number to size an ECC-to-S/4HANA migration and to track progress from the first scan through go-live.
Why a single score matters
Every ECC-to-S/4HANA business case stalls on the same question: how big is this, really? Estates are opaque. Twenty years of custom code accrete, nobody remembers why half of it exists, and a traditional systems-integrator assessment takes six to eight weeks and a seven-figure fee just to answer it. A Clean Core Score collapses that opacity into one comparable number a CIO can take to a board meeting.
"Clean core" is SAP's own principle: keep the standard system standard, and move extensions to a governed, upgrade-safe layer. The closer your estate already is to that principle, the cheaper and lower-risk your migration. The score simply measures the distance.
What goes into the score
Three inputs, weighted:
- Custom-object volume — how many Z/Y programs, exits, enhancements and custom tables exist relative to the standard footprint.
- Release age — older ECC releases carry more accumulated modification and simplification-item exposure.
- Customization spread — whether custom code is concentrated in one module or smeared across finance, logistics, and order-to-cash, which drives testing and risk.
From score to savings
The score is only useful if it connects to money. On a reference estate — a live ECC system — an evidence-weighted read found that 44% of custom objects were re-implementations of things S/4HANA now does as standard, and surfaced $1.9M in avoidable annual carry cost. Those are reference-estate figures; a customer's numbers come from reading their own system.
The point is that a Clean Core Score is not a vanity metric. Each point of improvement maps to specific objects you can retire, standardize, or keep — with the reason attached.
How to get your score
You can get a first, calibrated Clean Core Score from a few inputs about your estate — no system access required, in under a minute. A deeper, connected assessment reads your live system read-only, through a connector deployed inside your own environment; your SAP is never exposed to the internet.
Frequently asked
Is a Clean Core Score the same as SAP's Readiness Check?
No. SAP's Readiness Check is a technical simplification-item report. A Clean Core Score is a single normalized 0–100 benchmark designed for decision-making — comparable across systems and trackable over time — that factors custom-code volume, release age, and how broadly customization spreads across modules.
Do I need to connect my SAP system to get a score?
No. The free score is estimated from a few inputs about your estate. A connected assessment is an optional later step that runs read-only through a connector inside your own network — SAP is never opened to the internet.
What is a good Clean Core Score?
Higher is cleaner. The score is most useful as a trajectory: measure it before you migrate, then watch it climb as you retire and standardize custom objects on the path to a clean S/4HANA core.
See your own Clean Core Score.
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