The team treated the separation as an operating-model change, not a single cloud cutover. The sequence established the destination control plane first, moved collaboration and workloads in recoverable waves, and transferred the new environment into named operating ownership.
01
Map the complete separation boundary
Treat network, identity and Active Directory, endpoints, servers, applications, and data as one coordinated carve-out so Day-1 ownership is not split across incompatible assumptions.
02
Establish the new control plane
Build a greenfield Azure landing zone with role-based access, policy, guardrails, and cost governance before moving workloads that depend on those controls.
03
Sequence Microsoft 365, application, and data moves
Migrate collaboration, email, files, applications, and data while cleaning up Teams, SharePoint, and Exchange boundaries and using rehearsals plus rollback paths for cutovers.
04
Exit transition dependencies and stabilize
Clarify tenant, subscription, access, licensing, and remaining TSA ownership, then transfer the separated environment into runbooks, monitoring, SLAs, and managed operations.