Name the systems before you name the clouds
Teams often open a migration conversation by naming a cloud provider. That debate feels productive because brands are familiar. The harder work is naming the systems that still share a login table, a batch schedule, or a forgotten overnight export. Until those boundaries are written down, a “wave one” is just a slogan.
In our readiness assessments we ask for the names your on-call already uses — not the names on an architecture poster from two years ago. If two services still share a database user, they are not two migration units yet. If a reporting job still lands files on a file share that only exists in the old data centre, that job belongs in the inventory even when nobody wants to claim it.
Choosing a cloud later is fine. Choosing it before the inventory exists usually means the first cutover weekend discovers the shared secrets the slides omitted. Write the names first. Argue about vendors with a list in hand.