The goal of this thesis is to develop a software capable of handling event-based systems, providing the user the ability of modelling them thanks to an easy-to-use Graphical User Interface and, then, allowing to generate final code representing the system, which is editable by the user itself, if needed. The software, called GEM (Generic Event-based Modelling), exploits the framework developed by the Zirak S.r.l. company, which provides the APIs to deal with an event-based system: it allows the user to establish policies for event signalling, event dispatching and event handling behaviour(s). The tool chosen to design and develop the software is the Qt framework, given its C++ integration and its academic-use license, but also for its ability to ease the handling of GUIs for software and its ability to connect graphic and business worlds easily, through the usage of design facilities, such as signals/slots paradigm.