I am vice-chair of IFIP IP3 and chair of the Global Industry Council. This explanation came forward from ISACA who sits on both. I thought a good explanation so I am quoting directly.
There was a question posed about the connections/differences between COBIT and ITIL. Hope that the following is of assistance:
COBIT and ITIL have been used by information technology professionals in the IT service management (ITSM) space for many years. Used together, COBIT and ITIL provide guidance for the governance and management of IT-related services by enterprises, whether those services are provided in-house or obtained from third parties such as service providers or business partners.
Enterprises need to govern and manage their information and related technology assets and resources, and those arrangements customarily include both internal and external services to satisfy specific stakeholder needs. COBIT 5 aims primarily to guide enterprises on the implementation, operation and, where required, improvement of their overall arrangements relating to governance and management of enterprise IT (GEIT). ITIL provides guidance and good practice for IT service providers for the execution of IT service management from the perspective of enabling business value.
COBIT 5 describes the principles and enablers that support an enterprise in meeting stakeholder needs, specifically those related to the use of IT assets and resources across the whole enterprise. ITIL describes in more detail those parts of enterprise IT that are the service management enablers (process activities, organizational structures, etc.).
· COBIT is broader than ITIL in its scope of coverage (GEIT). It is based on five principles (meeting stakeholder needs; covering the enterprise end to end; applying a single, integrated framework; enabling a holistic approach; and separating governance from management) and seven enablers (principles, policies and frameworks; processes; organizational structures; culture, ethics and behavior; information; services, infrastructure and applications; people, skills and competencies).
· ITIL focuses on ITSM and provides much more in-depth guidance in this area, addressing five stages of the service life cycle: service strategy, service design, service transition, service operation and continual service improvement.
Also, COBIT and ITIL are well aligned in their approach to ITSM. The COBIT 5 Process Reference Model, as documented in COBIT 5: Enabling Processes, maps closely to the ITIL v3 2011 stages.
The distinction between the two is sometimes described as “COBIT provides the ‘why’; ITIL provides the ‘how.’” While catchy, that view is simplistic and seems to force a false “one or the other” choice. It is more accurate to state that enterprises and IT professionals who need to address business needs in the ITSM area would be well served to consider using both COBIT and ITIL guidance. Leveraging the strengths of both frameworks, and adapting them for their use as appropriate, will aid in solving business problems and supporting business goals achievement.