Implementing ITIL is considered difficult by most and quite daunting, however this depends on the level of maturity the organisation is seeking and what is generally recommended is a staged pathway to move to an optimised state. Smaller organisations should cherry pick the processes and components within those processes to avoid over complicating the implementation.
Implementations have been successful where they have had support / sponsorship from senior management, project managers, persons dedicated to performing the role of process owner and individual roles within ITIL. Other critical success factors include training and communication. Unfortunately, organisations that have implemented ITIL as a service management framework have often been unable to justify the operational costs with the so-called benefits the framework offers. For this, in most cases it has drifted by the side line and remnants of ITIL are present, but the lack of commitment and management drive has disappeared.
Most organisations have implemented:- Incident Management, Service Desk, Change Management, Release Management, Service Level Management and Configuration Management (Service Support).
Some organisations have implemented the entire framework, so Service Support and Service Delivery. These are v2 ITIL and not many organisations have upgraded to v3.
Roles and Responsibilities (people holding two hat roles, the whole argument that you can only have one master unless the person is allowed a 50/50 split, depending on the commitments of their contribution to a particular process.
Cost / Benefit Analysis to be performed prior to implementation.
Exercise to determine costs before implementation and after to understand operational cost savings.
Engage all stakeholders and communicate effectively throughout the implementation to ensure success.
Engage existing suppliers in the implementation for the development of workable SLAs
Consider tools that will complement the process early in the planning phase
Understand what the ITIL organisation will look like 1/3/5 years down the track
On a side note, most organisations actually perform the processes that are described in the ITIL framework but are reluctant to implement because of the controversy of the so-called benefits. ITIL provides a common framework and terminology in which organisations can operate, but I guess the question I have is, as long as the organisation has standards, policies, and internally developed frameworks pertinent to their business model – why implement ITIL?