The concept of patterns was first developed in the context of architecture and is now widely used in different fields such as software design or workflow design. In the last years the idea of patterns is also used to incorporate privacy in the life-cycle of Information Technology (IT) services. Concerning privacy and security, patterns are mainly used in the design phase of IT services in the form of design patterns. In this paper we propose a pattern-based approach to assess the compliance with privacy regulations continuously during the operation phase of an IT service. The central idea of patterns in this area is to provide an abstract representation of typical automated processing procedures for the processing of personal data. Since these patterns represent abstracted versions of workflows, we use as an illustration diagrams with a notation derived from Business Process Management Notation (BPMN). The aim of the approach presented here is to increase the transparency of assessments for all participants and to allow an easy adjustment of existing assessment results when changes occur.