Decommissioning the Old System
Decommissioning the old (or 'legacy') system is often more difficult than perhaps imagined. Over time, many components of a system have become established and these must be carefully and cleanly removed, with some being stored elsewhere, and then replaced by the same components for the new system. Depending on your implementation model the decommissioning phase could coincide with the new system go live (once performance of the new system is deemed to be satisfactory and has 'bedded down' - as you may need to revert to the old systems if invoking contingency plans) or could be some way down the line if you are running a parallel, phased or pilot implementation.
Legacy components can be spread over several locations and may comprise:
- Standards and systems documentation (including original system design and tendering documentation)
- Supplier contracts
- Escrow agreements and software deposits
- System testing material
- Current and archived system databases - source code, data, backups
- User access and security details
- System reports
- Training material
- User manuals
The complete list of components should be determined with the support function(s) for the legacy system to ensure that everything is listed and properly decommissioned once the old system has been switched off and it is certain that it will not be required again.
Before the system is switched off, the necessary components should be secured onto long-term storage in a format which will be readable in the long term and which complies with legislation and the organisation's needs to access historical data. You can find out more about record retention in the Records Management infoKit. If there is a need to access old information, special programs may need to be written to read and present it in a meaningful format.
Once the required data is secure, the system can be switched off and user access discontinued in line with your implementation model and support requirements.
As with any part of an implementation, it is of paramount importance to consult and communicate with all stakeholders about the plans for decommissioning the old system(s).
