State Government · Legacy System Retirement

Context

A state government was preparing to retire multiple legacy systems supporting critical operations. While functionally obsolete, these systems remained deeply embedded due to their role as the only accessible source of historical data.

Challenge

The organisation faced a constrained and high-risk environment:

• Legacy systems could not be retired without impacting operational, investigative, and compliance activities
• Data was tightly coupled to ageing applications, with no standalone access pathway
• Users remained reliant on legacy interfaces due to familiarity and lack of alternatives
• Platforms were becoming increasingly fragile, difficult to support, and costly to maintain
• Ongoing exposure to licensing, security, and data retention risks

Systems needed to be retired but could not be turned off.

Approach

Adeptus designed and executed a structured decoupling of data from legacy systems without disrupting business continuity. This required:

• Designing a target-state architecture that preserved data integrity, accessibility, and control
• Establishing a secure, governed archive capable of supporting real operational use cases
• Migrating and validating legacy datasets where data quality, structure, and lineage were inconsistent
• Implementing role-based access models to replicate and improve existing access patterns
• Delivering a low-operational, scalable platform that would not recreate the problem in a new form

The solution had to hold technical complexity, user behaviour and organisational risk in balance at the same time.

Outcomes

• Enabled safe decommissioning of legacy systems previously considered too risky to retire
• Removed ongoing support burden, licensing costs, and infrastructure overhead
• Improved security and governance of retained data
• Preserved trusted access for operational and compliance use cases
• Established a repeatable model to systematically reduce legacy debt