Improving model-based verification of embedded systems by analyzing component dependences

Embedded systems in automobiles become increasingly complex as they are intended to make vehicles even more safe, comfortable, and efficient. International norms like ISO 26262 and IEC 61165 postulate methods for the development and verification of safety critical systems. These standards should ensure that the dependability and quality of the embedded systems is maintained while their complexity and interdependence increases. Yet, the standards do not contain concrete methods or tools for their fulfillment. As concerns classic techniques for dependability analysis they either base on system analysis by means of Markov analysis or on reliability estimation from a usage perspective. Treating the system only from one perspective, however, is a drawback as the system analysis neglects functional or non-functional dependences of the system. These dependences can directly influence the reliability in the field usage. In this paper we present our approach to combine component dependency models with usage models to overcome these deficiencies. It is possible to identify usage scenarios which aim for critical dependences and to analyze the interaction of components inside the system. On the other hand usage scenarios can be assessed whether they meet the desired verification purpose. The component dependency models reveal dependences that were not identified before, because it allows the extraction of implications across functional and non functional dependences like memory, timing and processor utilization.