Experience from Application of Semi-Automatic Fault Tree Synthesis to Reliability and Availability Analysis of Ship Systems

The increasing complexity and scale of ship machinery systems pose significant challenges to failure analysis. There is a tendency to optimize systems via the introduction of new technologies in order to achieve, for example, improved energy efficiency or expand the operation area to extreme environments. Although such improvements are welcome, they typically also cause significant design changes that need to be supported by dedicated reliability and availability analysis. Recently, substantial work towards addressing these challenges has resulted in semi-automatic approaches to the synthesis of system failure prediction models, such as fault trees. This paper presents, with the help of application examples, the experience gained from the use of the semi-automatic fault tree synthesis method and tool “Hierarchically Performed Hazard Origin & Propagation Studies” (HiP-HOPS) together with the simulation platform SimulationX. Beyond the automation and simplification of reliability and availability prediction, a further benefit of the approach presented in the paper is the use of the same system model for the dual purpose of behavioral simulation and reliability analysis. This enables a fast and efficient consideration of design modifications avoiding the need of updating simulation and reliability models separately, and therefore facilitating an easy iteration of the design process and useful model-based interpretation of analyses by designers, operators or approval authorities even in complex systems.