Developing Safety-Critical Systems with UML

Safety-critical systems have to be developed carefully to prevent loss of life and resources due to system failures. Some of their mechanisms (for example, providing fault-tolerance) can be complicated to design and use correctly in the system context and are thus error-prone. We show how one can use UML for model-based development of safetycritical systems with the aim to increase the quality of the developed systems without an unacceptable increase in cost and time-to-market. Specifically, we describe how to use the UML extension mechanisms to include safety-requirements in a UML model which is then analyzed for satisfaction of the requirements. The approach can thus be used to encapsulate safety engineering knowledge. It is supported by a prototypical XMI-based tool performing the analysis.