The purpose of this thesis is to reveal how Information Technology  Infrastructure Library (ITIL) should be implemented in an organization in  an efficient and effective way to achieve the goal of reducing wastage, cutting costs and increasing customers’ satisfaction. There are many books dealing with the ITIL. But these publications do not prescribe how to adopt, adapt or implement the guidelines as part of a service management strategy; it would seem useful to explore implementation strategies which are employed by organizations when they are using ITIL “best practices”.

This paper seeks to take a study of “How to implement ITIL successfully in organizations”, which could be subdivided into questions of “What steps are necessary to implement ITIL” and “what factors are critical within implementation process”. Although previous researches have made some recommendations generally, this paper investigates the question on that base through comparing consultants’, organizations’ opinion and previous researches.

This study begins with an overview of ITSM, ITIL, and critical success factors and steps of ITIL implementation. Information about the critical success factors and steps of ITIL implementation were acquired through interviews, emails and questionnaires from responsible staff in some major representative consultancy and organizations.

The outcomes of our research are fourteen significant steps to implement ITIL and some success factors during implementation, which are vital to have a prosperous ITIL implementation. This research makes a guideline for organizations to understand and carry out the ITIL implementation efficiently.