Computerized clinical guidelines (CCG) are effective instruments for standardizing, monitoring and optimizing medical treatment processes. Nevertheless, due to barriers in flexibility, transferability and acceptance, the widespread use of CCG in clinical practice is not yet common. To overcome those issues, we present a concept on how to use real world data to evaluate CCG and to recommend improvements. As a first result, we defined an algorithm to extract treatment processes based on the standardized Observational Medical Outcomes Partnership (OMOP) Common Data Model as well as their visualization using the graphical modeling language Business Process Model and Notation (BPMN).