Process mining techniques attempt to extract nontrivial and useful information from event logs. For example, there are many process mining techniques to automatically discover a process model describing the causal dependencies between activities. Several successful case studies have been reported in literature, all demonstrating the applicability of process mining. However, these case studies refer to rather structured administrative processes. In this paper, we investigate the applicability of process mining to less structured processes. We report on a case study where the process mining (ProM) framework has been applied to the test processes of ASML (the leading manufacturer of wafer scanners in the world).This case study provides many in...