Formal Schedulability Analysis and Simulation for AADL

Abstract

With rapid developments in science and technology, we now see the ubiquitous use of different types of safety-critical systems in our daily lives such as in avionics, consumer electronics, and medical systems. In such systems, unintentional design faults might result in injury or even death to human beings. To make sure that safety-critical systems are really safe, only using the traditional methods is not enough. Model-Driven Architecture (MDA) method is becoming the mainstream as the instrument of the people. Architecture Analysis and Design Language (AADL) is a modeling language standard brought forward by the Society of Automotive Engineers, Avionics Systems Division, et al, is becoming a research topic for many organizations and institutes. It is a kind of MDA method also. For safety-critical systems, we must verify all the important properties whatever the method we use. Among the properties, the schedulability problem is a very important problem in the real-time software. But, how to solve the schedulability problem in a practical AADL project is a new obstacle to us. In this paper, we use the linear hybrid automata to abstract the semantics of the software components explicitly, then try to use TIMES tool developed by Uppsala Univ and Furness tool developed by Fremont Associates, LLC to simulate the semantics of linear hybrid automata and the scheduling execution trace of AADL software components respectively. Finally, we compare the two methods and make a conclusion.