Which process analyses services that are no longer viable and when they should be retired?

Change Management controls the authorization and lifecycle of individual changes to the IT infrastructure; it does not make strategic decisions about retiring whole services from the portfolio.

Service Portfolio Management is responsible for evaluating all services across their entire lifecycle - from pipeline through catalogue to retirement. It assesses whether services continue to deliver sufficient business value and strategic alignment, determines when a service should be decommissioned, and formally moves it to the retired services section of the portfolio.

Service Level Management negotiates, agrees, and monitors SLAs with customers but has no mandate to assess service viability or recommend retirement of services.

Business Relationship Management focuses on maintaining a positive relationship between the service provider and business customers; it does not perform viability analysis or govern the retirement of services.