What is PSBA? It is the Public Sector Broadband Aggregation network — shared network infrastructure across the Welsh public sector, including NHS Wales. PSBA-class shared infrastructure provides the network underlay on which national NHS Wales systems run. In March 2026, a single PSBA-class failure took O365, EPMA, RISP, and radiology offline simultaneously across NHS Wales — four national clinical and administrative systems out of action together. The incident exposed how concentrated NHS Wales's dependency on a single shared-infrastructure layer has become.
What PSBA does
PSBA — Public Sector Broadband Aggregation — provides shared network infrastructure for the Welsh public sector, including NHS Wales. PSBA-class shared infrastructure is the network underlay on which national NHS Wales clinical systems run. When PSBA-class infrastructure is unavailable, the systems that depend on it are unavailable.
Status
In operational use. The March 2026 incident exposed structural concentration risk that has not been remediated.
The March 2026 incident
In March 2026, a single failure in PSBA-class shared infrastructure took four national systems offline simultaneously across NHS Wales:
- O365 — productivity / communications platform across the seven health boards.
- EPMA — Electronic Prescribing and Medicines Administration.
- RISP — Regional Imaging Solution.
- Radiology — additional radiology services.
This was the third consecutive year of major infrastructure failure affecting NHS Wales digital services. The 2024 and 2025 incidents originated at DHCW’s own data centre — near-identical cooling-failover failures, twelve months apart, each taking 32 services offline for hours. The 2026 incident was the PSBA network layer (a different supplier, contracted by Welsh Government, not DHCW). Different mechanism; same downstream signature — multiple national clinical and administrative services offline simultaneously for hours. See DHCW Data Centre for the 2024 and 2025 incidents, including the sanitisation pattern across the published minutes.
This is the operational manifestation of concentrated infrastructure dependency. A single failure point cascaded across four clinically-significant systems at once. The incident was recorded in DHCW board papers. Structural remediation — separating shared-infrastructure concerns so that a single failure cannot take out four clinical layers simultaneously — has not followed.
Why this matters structurally
PSBA illustrates a specific risk that the Blueprint analyses across multiple loops: when delivery is concentrated in one body using one set of shared infrastructure components, the failure modes are correlated rather than independent. Independent failures degrade gracefully; correlated failures cascade. NHS Wales digital infrastructure exhibits correlated-failure behaviour because it is structurally organised that way.
The remedy is architectural separation: shared standards-setting with distributed delivery and distributed infrastructure dependencies. This is the structural argument of Intervention 4: Flip the Model — the once-for-Wales monopoly produces single-point-of-failure dynamics even at the infrastructure layer.
Where this is discussed in the diagnosis
- Drift to Low Performance — PSBA-class outage cited as one of the dangerous-state indicators.
- Intervention 1: Competent Leadership — Action 6 names PSBA for clinical-safety triage.
- Intervention 4: Flip the Model — the structural separation that would prevent correlated-failure dynamics.
- Once for Wales — the monopoly framing under which PSBA-class concentration has been allowed to deepen.