Sicherheits- und Verfügbarkeitsanalyse komplexer Kfz-Systeme

In the dissertation-thesis in hand a methodology is developed, which allows to determine the failure-probability, availability, safety and economy of complex safety-relevant automotive systems in a closed model. This methodology is based on the fusion of fault-trees and Markov-chains to a hierarchical model.
The hierarchical modelling generates a qualitative as well as quantitative prediction of the above mentioned system-quality-parameters. Modifications during the development-process of a complex system can be integrated in the analysis with small effort.
In order to demonstrate the potentials of the hierarchical modelling, it was applied to determine the failure-probability, availability, safety and economy of a driving-stability-control-system. This system, which is called Drive-by-Wire was in the early research-phase, when the first safety and availability-analysis had been performed. As it turned-out, failures of the wheel-speed-sensors are mainly responsible for the unsafety of this system.
Therefore redundancy concepts were developed which yield tolerance against above
mentioned critical failures. Finally the influence of different redundancy concepts on the failure-probability, availability, safety and economy of Drive-by-Wire was determined by the hierarchical modelling.