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Abstract
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New drive concepts as well as advanced driver assistance systems and revised basic functions belong to the main innovation areas in today's automotive industry. Since thereby more and more electric / electronic components are integrated in modern passenger cars, the complexity is steadily increasing. Additionally, a crucial part of the innovations focuses on active and passive safety. Together, this creates tough demands on systems reliability and functionality which influence the development.
Addressing the development process of electric / electronic components for passenger cars, the ISO 26262 "Road vehicles - Functional safety" came into effect in November 2011 ([1]). This standard introduces a safety lifecycle which "encompasses the principal safety activities during the concept phase, product development, production, operation, service and decommissioning" ([1], part 2, p.3) and which can be seen as a guideline that demands a risk-based development approach with seamless traceability.
Already in the beginning of this safety lifecycle, in particular during the concept phase (cf. [1], part 3), a hazard analysis and risk assessment needs to be performed for the item under development. Within this process, hazards are identified, combined with possible operational situations for the car, and relevant outcomes of these combinations, namely the hazardous events, are classified to determine the automotive safety integrity level (ASIL) for the item.
In this paper we address this hazard analysis and risk assessment. We developed a formalized hazard description language that enables a precise formulation of hazardous events based on four potential contributing factors. Moreover, it is shown how safety goals can be derived from these formalized hazardous events. In a further step it is described how the concepts presented in the paper on the one hand permit checking the implemented safety measures with respect to the risk mitigation which is achieved and on the other hand enables the application of model-based safety analyses in order to verify safety characteristics.
Language: en |