Information systems help organizations manage their entities with innovative technologies. These entities are often very different in nature. In this paper, we consider a business process level based on a set of Business Process Model and Notation (BPMN) models and a software system level based on a Unified Modeling Language (UML) class diagram. The differences between these entities make them difficult to align. In addition, an organization's BPMN models may be designed by different teams, which can cause syntactic and semantic heterogeneities. We present the first step of our proposed approach for aligning a software system level with a business process level without conflict (redundancy and lost information). Syntactic and semantic rules based on ontologies and other resources for comparing BPMN models are described, as well as a process for transforming BPMN models into UML model.