The technical plan was solid. Environment assessed, dependencies mapped, tools staged, and cutover window verified.

What was not in the plan, however, was the user that had a shared email address that no one documented. Not in IT’s files, not in migration checklists, not found during discovery.

The problem was discovered the morning after the cutover, when someone could not access a service they had been using for three years.

This occurs on almost all migrations. Not because people were careless – but because environments accumulate things with time that are not documented in formal documentation. Shadow configurations. Informal workarounds. Access that has been set up by a former employee.

The lesson isn’t to “plan harder.” Hyper Care – post-migration stability – is not optional. It’s when you find things that your plan didn’t know about and fix them before they become bigger problems.

Every migration has an unblemished cutover. Not every migration has an unblemished week after the cutover.

#Migration #M365Migration #IT