This project is about theoretical principles for using the metamodels of modeling languages in business process modeling. Using metamodels, different models and languages can be compared and transformed from one notation to another. Precise nature of metamodel-based models allows to simulate these models and execute in simulated or production environment. Research results are used in development of business process editors for UML Activity Diagram and BPMN modeling languages. Models created in these editors can be transformed from one to another using the MOdeling LAnguage (MOLA) transformation tool.