Abstract
Managing information technology services is becoming an increasingly difficult task. To support the management of IT services, different standards and methodologies have been developed. ITIL (short for IT Infrastructure Library) is the most commonly used best practice approach to effective IT Service Management to date. ITIL focuses primarily on what to do in order to ensure value of IT services, but it does not explain how to achieve this effectively. This shortcoming can be overcome by complementing the framework with other quality approaches to service management. In this context several methodologies are mentioned including the use of Six Sigma (6s) methodology. The statistical nature of the Six Sigma methodology enables us to analyze the vast amount of data gathered from the field of IT. Only after these value-based metrics are obtained can the overall health of the IT service be determined and the necessary improvement measures made. The aim of this paper is to analyze in detail the two approaches. We will establish a common link between them, with it the opportunity to complement ITIL with the Six Sigma methodology, and consequently set foundations for introduction of necessary measurable changes.