The decommissioning and archiving of legacy systems and data was carefully planned and funded as part of Business Transformation. In addition to delivering cost savings, this ensured the ethical and secure management of data.
A team of dedicated specialists
More than 400 applications were identified to be decommissioned by the end of the transformation. A team was established in 2017 to focus solely on identifying dependencies, planning the decommissioning of legacy applications and services, and disposal of hardware and data as appropriate.
Taking a staggered approach
As new technology was progressively introduced, and tax and social policy products were moved over to the new system, the team started turning off the technology which was no longer required.
Continuous engagement with key internal and external stakeholders was a critical success factor of this work.
Decisions around data
The team worked in partnership with system owners and users to understand what needed to happen to the data. Decisions were taken around whether data should be:
- moved to the new system
- archived in an appropriate system for a period
- transferred to Archives NZ (New Zealand) for permanent retention, or
- permanently and ethically deleted in line with legal requirements and Archives NZ Disposal Authorities standards.
Decommissioning the legacy core tax system
One of the more complex tasks of this workstream was switching off the old core tax system which had been in place for more than 30 years. Users of this system were given more than a year’s notice that it would be turned off, to ensure they were ready and able to support customers using the new system.
A full copy of the legacy database was archived to ensure any data not taken across to the new system was available if required. A limited number of people had access to this archive, but people could request access.
Identifying system connections and inter-dependencies
Working within a complex technology landscape, the team had to carefully navigate multiple dependencies and connections between systems and had to ensure people who still used legacy applications understood what was changing and were prompted to use new technology. This took time and a great deal of collaboration between multiple parties.
Critical success factors
A few key things contributed to the successful completion of this work:
- Having the right people on board - people with deep knowledge and understanding of who owns which systems, and the inter-dependencies between systems.
- Having people with the tenacity to work through what was in the data centre.
- Having supportive leadership in place to guide and support the team.
- Having the right governance forums in place.
- Continuous engagement and coordination with people and teams across Inland Revenue.
- Continuous information sharing, with full transparency of what was happening.
After more than 5 years, the team reached the final milestone on 31 March 2022 when the final few applications were turned off.