The problem was not the systems. It was the absence of a shared model.
Each entity held valid information about its own estate. What was missing was a common language: one metamodel and repository through which those views could be compared, aggregated and governed.
One metamodel, one repository
A single shared EA platform was established across all entities, with a common metamodel defining how applications and technology are described. Automated inventory through systemic integrations then populated it with real data rather than self-reported spreadsheets.
From inventory to decisions
Analytical blueprints turned the repository into visual models for strategic decisions, while a solution acceptance process gave the sector a rule set for evaluating new proposals against the reference architecture.
A repository records what exists. A reference architecture decides what comes next.
An active governance model now keeps the architecture coherent as it evolves, with formal processes owned by the sector rather than by any single project.