Most importantly, a detailed comparison between ITIL V3 and V2 reveals that all the main processes known from ITIL V2 are still there, with only few substantial changes. In many instances, however, ITIL V3 offers revised and enhanced process descriptions.
The main difference between ITIL V3 and V2 is the new ITIL V3 Service Lifecycle structure: ITIL V3 is best understood as seeking to implement feedback-loops by arranging processes in a circular way.
This means the old structure of Service Support and Service Delivery was replaced by a new one consisting of the five ITIL V3 core disciplines:
- Service Strategy determines which types of services should be offered to which customers or markets
- Service Design identifies service requirements and devises new service offerings as well as changes and improvements to existing ones
- Service Transition builds and deploys new or modified services
- Service Operation carries out operational tasks
- Continual Service Improvement Improvement learns from past successes and failures and continually improves the effectiveness and efficiency of services and processes.
ITIL V3 complements the processes known from ITIL V2 with a number of new processes and puts more emphasis on producing value for the business.
Due to the new Service Lifecycle structure, all interfaces between the ITIL processes were changed in order to reflect the new ITIL V3 process structure; so even if processes in ITIL V3 and V2 are broadly identical, their interfaces have changed. Example: The Incident Management process must now link to the Service Design processes, although a comparison between Incident Management in ITIL V2 and V3 reveals that the process itself did not change substantially.