Methodology

The Data Center Readiness Index ranks the 27 EU member states on their suitability for large-scale data center deployment. It aggregates pan-European and national data across eleven dimensions to give site-selection teams, infrastructure investors, and policy analysts a defensible, reproducible basis for comparing markets.

Each country is scored 0–100 on every dimension. The published ranking uses a rank-based composite; a weighted geometric-mean composite is computed from the same inputs and reported alongside it as a robustness check. The Spearman rank correlation between the two composites is published with each release.

The Index ranks countries on raw operating-environment quality, not on existing campus footprint. A market where capital has already accumulated may rank lower than its current footprint suggests; operators build there by engineering around constraints (custom interconnection, closed-loop cooling, premium power contracts) that a new entrant would not start with.

Each indicator is winsorized to cap extreme values, then normalized to a 0–100 scale. Indicators where lower is better (electricity price, interruption minutes, hazard exposure, water stress) are inverted so that 100 always means best in class. Indicators are combined within each dimension, and dimensions are combined into the composite, using fixed weights.

The published ranking uses a rank-based composite. A weighted geometric-mean composite is computed from the same inputs as a robustness check: the geometric mean is non-compensatory, so a country cannot trade catastrophic weakness on one dimension off against strength on another. The Spearman rank correlation between the two composites is reported with every release as a witness to their structural agreement.

Dimension weights reflect operator priorities surfaced through expert review and are calibrated with our European partner network. The exact weights are part of the calibrated methodology.

Countries are assigned to one of four quartile tiers over the 27-country ranking, recalculated each release: Top Quartile (ranks 1–7), Above Average (8–14), Below Average (15–20), and Bottom Quartile (21–27).

Markets that fall over the missing-data threshold are designated Insufficient Data and are not assigned a rank.

Every published ranking is tied to a release identifier that records the weights used, the source-data vintages, and the timestamp of the run. Rerunning with the same inputs reproduces the scores exactly, and published rankings are never overwritten.

Weight sensitivity is tested by perturbing each dimension weight and observing how ranks move; top-tier countries are expected to remain stable.

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Saltelli, A., Ratto, M., Andres, T., Campolongo, F., Cariboni, J., Gatelli, D., Saisana, M., & Tarantola, S. (2008). Global Sensitivity Analysis: The Primer. John Wiley & Sons, Chichester.