Service transition

Service transition is the stage of IT service management, defined in ITIL, that moves new or changed IT services into live operation while controlling the risk to services already running. It sits between service design, which specifies a service, and service operation, which runs it day to day.

The work includes change management, release and deployment planning, testing and validation, keeping the record of configuration items up to date, and handing knowledge and documentation to the teams that will support the service. ITIL 4 describes these activities as separate practices rather than one lifecycle stage, but the term is still widely used.

In software teams, much of service transition is now carried out through CI/CD pipelines, automated tests, infrastructure as code and staged rollouts, which make releases smaller, repeatable and easier to roll back.