Nowadays an important tool of design modeling is to be able to handle the complexity of IT systems. Amongst the modeling languages, the languages, that support the designing of state-based behaviour models, have an important role. One of this kind is the statechart language, which extends the statechart fromalisms with high-level constructions.
The goal of the Gamma framework, which is developed in our university, is to support the designing of distributed, state-based systems with modeling languages, verification and code generation. The tool is based on open-source softwares to create the individual models. It provides formal verification, so engineers can be certain about the correctness of the designs. But formal verification is slow, resurce-intensive, therefore it would be worth extending the tool with such methods, that are capable of providing feedback to engineers right from the beginning of the designing process. The goal of my work is to extend this tool with such a modeling language and validation, that help engineers to notice mistakes in the earliest possible phase of designing and to force the creation of correct design models. First of all in my thesis, I present the Gamma framework, then I propose a solution to support the state-based modeling with validation constraints. To do that, I've created a new, simpler state-based modeling language and the adherent validation constraints. I've designed the component and integrated the Gamma framework with this new component supporting the creation of state-based models.