K. Hinkelmann (✉) • E. Laurenzi • A. Martin • B. Thönssen FHNW University of Applied Sciences and Arts Northwestern Switzerland, Riggenbachstrasse 16, 4600 Olten, Switzerland e-mail: knut.hinkelmann@fhnw.ch Ontology-Based Metamodeling Knut Hinkelmann, Emanuele Laurenzi, Andreas Martin and Barbara Thönssen Abstract Decision makers use models to understand and analyze a situation, to compare alternatives and to find solutions. Additionally, there are systems that sup- port decision makers through data analysis, calculation or simulation. Typically, modeling languages for humans and machine are different from each other. While humans prefer graphical or textual models, machine-interpretable models have to be represented in a formal language. This chapter describes an approach to model- ing that is both cognitively adequate for humans and processable by machines. In addition, the approach supports the creation and adaptation of domain-specific mod- eling languages. A metamodel which is represented as a formal ontology determines the semantics of the modeling language. To create a graphical modeling language, a graphical notation can be added for each class of the ontology. Every time a new modeling element is created during modeling, an instance for the corresponding class is created in the ontology. Thus, models for humans and machines are based on the same internal representation. Keywords Modeling, ontologies, metamodel, enterprise modeling, domain-specific modeling language 1 Introduction Decision makers use models to understand and analyze a situation, to compare al- ternatives and to find solutions. Business process models, for example, enable the identification of potential improvements and the communication of process variants with stakeholders. Enterprise models serve as a baseline for changing the enterprise. Engineers use models as blueprints for planning and construction. Models describe and represent the relevant aspects of a domain in a defined lan- guage. There are many different kinds of modeling languages: graphical models, conceptual models, mathematical models, logical models. Even textual descriptions can serve as models. The choice of the modeling language depends on what the models is used for and who is using the model. General-purpose modeling languages such as UML have the advantage that they can be used to represent any kind of information. However, they have the disad-