Preparation.
ESTABLISH
What moves, and what does not What it depends on How much data How long the transfer will take
CLEAN UP FIRST
Delete what is no longer needed Agree the structure
PREPARE
The destination, configured and tested A verified copy at the destination A rollback plan
PLAN
The sequence and the timing Who does what How you verify What acceptable downtime is
RECORD BEFORE CHANGING
Every DNS record Current configuration Current permissions
DURING
Migrate in stages where possible Verify each stage
AFTER
Test every function, not the obvious one Check permissions and sharing Check integrations and scheduled tasks Check mail sending
KEEP
The source, until verification is complete and confidence established
TELL PEOPLE
What changed and where things now live.
