Decommissioning Before the Data Is Ready
A health authority runs six patient-admin systems and three integration engines. The target is a single patient record. The CIO wants four systems decommissioned within 12 months. A data assessment finds the patient identifier in nine formats, no enterprise data owner, and two clinical-safety-critical systems. One legacy system has 2,000 custom interfaces. The application portfolio catalog is incomplete, and no interface catalog exists. A regulator requires records retention for 25 years.
1. What Phase C artefacts and sequencing are needed before decommissioning?
Read the worked answer
Before any decommissioning, Phase C needs a baseline data and application architecture: patient identifier formats and reconciliation rules, data entities and ownership, data lifecycle and retention, an application portfolio catalog, and an interface catalog. Then a gap analysis to the single-patient-record target. The sequence matters: master data and identifier reconciliation first, interface migration second, application retirement third. The 2,000 interfaces are a dependency map, not a detail to be discovered during cutover. Clinical-safety-critical systems need clinical risk assessment and retention archiving before retirement. The 25-year retention requirement means 'decommission' may mean archive-and-replace, not delete.
2. How should the architect balance the CIO's 12-month decommissioning target with safety and retention?
Read the worked answer
Treat the 12-month target as a planning constraint, not a commitment to retire all four at once. Propose transition architectures: retire the lowest-risk, non-clinical system after data reconciliation; keep safety-critical systems until replacement is proven and records are archived; migrate shared interfaces to the integration platform. Use risk-based sequencing and architecture requirements to show the CIO what can safely be achieved in 12 months and what cannot. If the CIO insists on the full date, record the residual clinical and regulatory risk and require Architecture Board acceptance. The architect should not let a date override patient safety or retention obligations.