Over years, information technology (IT) has been a fundamental success factor by its contribution to the
efficiency, profitability, and growth for enterprises. In time, IT has become a strategic partner of companies. As a consequence, the role of IT has evolved and organizations have become to see IT as a part of business rather than a separate unit. Thus, IT services have to function continually to make enterprises reach their business goals. However, IT services’ working uninterruptedly is almost impossible due to many constraints (i.e. hardware and software requirements, budget etc.) and strict working conditions in the digitalized age (i.e. working 24 hours a day and 7 days a week, rapid change, complexity etc.). Therefore, there is a need for optimizing IT services’ availability. This study suggests a new methodology to meet this requirement. For this aim, after preparing an efficient IT service catalog and determining right relationships between services, IT service level is optimized by means of a new mathematical model. Moreover, the proposed method is applied with both random instances and a real case study of a big Turkish IT company serving to a finance group. It is analyzed that the proposed method provides efficient service level.

Keywords
Information technology, service management, service level optimization, mathematical model, case study