Hierarchically Performed Hazard Origin and Propagation Studies

This paper introduces a new method for safety analysis called HiPHOPS (Hierarchically Performed Hazard Origin and Propagation Studies). HiP-HOPS originates from a number of classical techniques such as Functional Failure Analysis, Failure Mode and Effects Analysis and Fault Tree Analysis. However, it extends, automates and integrates these techniques in order to address some of the problems currently encountered in complex safety assessments. The method enables integrated assessment of a complex system from the functional level through to the low level of component failure modes. It mechanises and simplifies a large part of the analysis, the development of fault trees, and can guarantee the consistency of results. HiP-HOPS is currently supported by a tool called the Safety Argument Manager (SAM). In this paper we introduce the method and we show how it has helped us analyse and improve the safety of a distributed brake-by-wire system for cars.