In the lifecycle of every application there will come a time when it must be retired. Given the inevitability of this outcome it’s surprising that so little time is spent planning the decommissioning during the application’s acquisition.
For convenience the words application and system are used synonymously throughout this article.
There are many reasons why a system could be considered legacy. It may be unreliable, difficult or expensive to change. Perhaps it’s no longer required or the vendor has gone out of business. Whatever the reason, when its time is up it has to go. Replacing a legacy system the right way will minimise any possible disruption to the business.
Some things to consider when replacing any legacy system
- How much of the existing functionality is still required?
- Will the data need to be migrated and what will this involve?
- Will a minimal installation still be required in order to provide access to historic data?
- Is a phased switch-over to the new application required or will a big bang approach suffice?
- How will system interoperability be affected?
This is not an exhaustive list, but it’s a good place to start and will serve to stimulate discussion.
When your list of questions is complete arrange a meeting with all of the stakeholders in order to discuss them. Be sure to include your questions in the meeting agenda and send them along with the meeting invite. If you have a large number of stakeholders you may find it more productive to arrange a number of smaller meetings with about half-a-dozen people (plus the facilitator). Doing so should help to create a cosy atmosphere where everybody feels able to participate.
The purpose of this meeting is to:
- Understand the business context and the application landscape.
- Formulate a comprehensive list of migration requirements.
Take care to record the key points from each meeting and use these to create a requirements document that can be signed-off by the stakeholders.
Once the requirements for the system migration have been agreed, the rest of the process is the same as for any other project. That is create a plan, form a team and get cracking.