The inherent quality of business processes increasingly plays a significant role in the economic success of an organization. More and more business processes are supported through IT processes. In this contribution, we present a new approach which allows the continuous quality improvement of IT processes by the interconnection of IT Infrastructure Library (ITIL) reference model and process mining. On the basis of the reference model, to-be processes are set and key indicators are determined. As-is processes and their key indicators derived by process mining are subsequently compared to the to-be processes. This new approach enables the design and control of ITIL based customer support processes which will be trialed in a practice case of a customer relationship management (CRM) system. The procedural models, as well as its results, are introduced in this publication.