ITIL is the abbreviation for the guideline IT Infrastructure Library, developed by CCTA, now the OGC (Office of Governance Commerce) in Norwich (England) developed on behalf of the British government. The main focus of the development was on mutual best practices for all British government data centers to ensure comparable services. Today ITIL is the worldwide de-facto-standard for service management and contains broad and publicly available professional documentation on how to plan, deliver and support IT service features.

In the beginning ITIL was a series of more than 40 manuals about IT service management consisting of 26 modules. This first large library is also known as ITIL 1.0. Between 2000 and 2004 due to the continuous service improvement and the adaption to the current situations in the IT environment ITIL 1.0 was modernized in a major release and combined into eight core manuals: ITIL 2.0. In the early summer of 2007 ITIL 3.0 was published. It established a completely new structure. It comprises three major areas:

• ITIL Core Publications
• ITIL Complementary Guidance
• ITIL Web Support Services

The ITIL core publications form a set of five manuals that illustrate a lifecycle model from service strategy, service design up to continuous service improvement. The manuals contain these titles and subjects:

•  Service Strategy
•  Service Design (models for productive operation)
• Service Transition (service implementation/launch)
• Service Operation (productive operation of services)
• Continual Service Improvement