Implementing the IT Infrastructure Library (ITIL) IT service management (ITSM) best practices is an expensive and time consuming endeavour. In spite of guidance, many organisations experience failed attempts before experiencing success. A detailed analysis of 12 organisations\u27 ITIL ITSM improvement projects shows that tangible business value is obtainable but that necessary conditions must be met. The analysis reveals that, while the organisations used a variety of strategies, approaches and practices in implementing ITIL and also experienced differing challenges in their journeys, there is a ‘sweet spot’ of organizational structuring and practices for necessary conditions which appear to be required for success. Change management themes found across the cases that appear to encompass the necessary set of conditions include strategy, scope, management approach, workforce planning and development, tools, vendors, outcomes, culture, customer influence, motivation and communication. Key aspects of these themes with case examples are presented