Kausch, HendrikPfeiffer, MathiasRaco, DeniRath, AmelieRumpe, BernhardSchweiger, AndreasGroher, IrisVogel, Thomas2023-02-132023-02-132023https://dl.gi.de/handle/20.500.12116/40202The development of avionics message communication systems is expensive due to their complexity and the need to get them accepted by the certification authorities. We need to develop high-integrity software, but we also face cost pressure. For managing complex large systems, several time-synchronous modeling languages have been proposed. While these are appropriate for hardware specifications, when it comes to specifying distributed software systems, an event-based specification style is better suited. We present an event-based specification theory based on the framework Focus by giving the signatures and data types for specifications using event automata. For this, we capture message processing order as a further dimension of non-determinism by specifying a general timed merge component. These event automata can represent underspecification of behavior, and a refinement calculus can be applied to these for a stepwise reduction of non-determinism. Furthermore, we present the necessary concepts for enabling a user-friendly specification and simulation of event-based systems by using the architecture description language MontiArc. Finally, we evaluate our approach by performing a top-down architecture design of an avionics case study and demonstrating event-based specifications of requirements in MontiArc. The presented methodology improves the management of complexity, reduces costs, and increases the system quality.enevent-based componentsautomataformal verificationmodel-driven developmentunderspecificationdistributed systemsavionicsText/Conference Paper10.18420/se2023-ws-17