The IT Infrastructure Library (ITIL) v3 framework organizes IT service management into five distinct service lifecycle stages, encompassing 26 core processes designed to align IT services with business objectives. This structured methodology manages services from initial strategic concept through design, transition, and operation, while driving continuous improvement across the entire service ecosystem.

The first stage of the lifecycle is Service Strategy, which establishes the overarching business intent, financial models, and governance policies for the IT service portfolio. This stage comprises five processes: Strategy Management for IT Services, Service Portfolio Management, Financial Management for IT Services, Demand Management, and Business Relationship Management. Together, these processes evaluate market needs, manage capital investment, align IT offerings with customer requirements, and balance resource supply against business demand.

The second stage, Service Design, translates strategic objectives into detailed, operational blueprints for new or modified IT services. This phase encompasses eight distinct processes: Design Coordination, Service Catalog Management, Service Level Management, Availability Management, Capacity Management, IT Service Continuity Management, Information Security Management, and Supplier Management. These processes ensure that technical architectures, service level agreements, continuity plans, vendor relationships, and security controls satisfy performance and availability targets prior to live deployment.