In the OrdinoR framework for organizational model mining, we outlined three tasks to be addressed in discovering organizational models from an event log (Section 2.4). Those are: (i) determining execution contexts based on the subimport log, (ii) determining resource grouping, i.e., groups of resources sharing similar behavior, and (iii) determining how to link execution contexts to resource groups to describe their involvement in process execution. Chapter 3 is devoted to solving the first task. This chapter introduces a systematic approach to discovering organizational models, covering all three tasks. We will look into the concrete challenges and discuss alternative methods for addressing them. We will also explain what and how user knowledge assists in configuring those methods.