When migrating from legacy platforms like Groupwise, Notes, Exchange 2003 or other platforms to Exchange 2013 or Office 365, our experience shows that you are better to run the cut-over as a single event. That is to say that we strongly believe that it is much less costly and risky to run an email migration in a single event over a weekend. The organization prepares for the migration for months, making sure all is ready and then migrates all the users in one single swoop. Once the event has happened, we take a few days to mitigate any issues.The benefits of this type of migration strategy are the following:
- The impact to end-users is much smaller.
- All users have access to the same ressources immediately.
- There is no interoperability, conference room booking issues and other coexistence, functional differences and discrepancies or issues.
- There is also no need to setup and continuously maintain a coexistence setup.
These migrations are much less costly. They are high intensity. Usually, the whole IT team is on standby for that one weekend and ready to help where required. But this is really a plus as it is easier to gather staff and require special efforts around a specific event than when a project take months. There is no scheduling, communication and logistical issues related to preparing user groups and maintaining exact migration schedules.
Because the whole organization is moving at the same time, there is energy that can be leveraged. Communications to ensure that expectations are set properly can have more impact. Employees help each other where required because they understand it is a point event. Because it is a point event, special help desks can be setup to help users with mobile device and regular help desks can be augmented by trained staff to filter support calls. It would not make sense financially to do this over many months. Finally, because you prepare ahead of time and inject old data early, you can also allow the users to go and log into the new mail system, get accustomed to using O365/Exchange with their historical data, and reduce the stress of the migration.
In ongoing, long-term migrations, users and IT staff can get quickly tired of dealing with the migration. Small issues can be very painful – death by a thousand cuts. Many migrations, that ran with that model were cancelled mid-way and reverted back because pre-planning was reduced and issues were not appropriately accounted for upfront. Migrating an organization's email system is not something you just start and learn as you go.
Single weekend migrations require quality automation tools, and the use of these allows better visibility in the overall process and a reduction in the required staff. The cost is smaller because there is less of a staff burden than ongoing migrations. For example, one data migration project we completed for 22,000 users required only 1.5 full time staff members. The rest of the resources were focused on user support.
In short, these migrations take less resources and when planned properly have less impact on your important end users.