ITIL® Service Operation Publication, 2011 Edition
The ITIL 2011 Editions have been updated for clarity, consistency, correctness and completeness. ITIL is based upon a lifecycle approach and the core guidance consists of five publications: ITIL Service Strategy, ITIL Service Design, ITIL Service Transition, ITIL Service Operation, ITIL Continual Service Improvement. Each of the five publications represents a stage in the ITIL service lifecycle. With each stage influencing and relying upon the others, the lifecycle moves cyclically from service strategy (where the business requirements are set) to the design, transition, operation and continual improvement of IT services. The lifecycle is driven by business needs and requirements and has a continual feedback system built into every stage to ensure that an organization's service management offering continues to provide measurable value to the business. The process-based framework of the service lifecycle can be adopted and adapted by organizations of all types and sizes.