Computer-aided identification of system vulnerabilities and safeguards during conceptual design

This work presents an approach to helping engineers to begin to address safety risks and to capture information during conceptual design, for use in early hazard analysis. Complex system accidents are hard to understand when they happen and hard to identify before they happen. Our goal is to aid early identification of this type of potential accident. We describe progress in developing a prototype hazard identification tool to help engineers capture design features of systems and components. We describe terminology for classifying and describing system functions, problems, vulnerabilities and safeguards. This terminology can be applied to hardware, software and human factors. Conceptual design information is mapped to a library of component models, to support generation and simulation of system accident scenarios. We describe a strategy for identifying potential system accident scenarios, based on an analysis of types of sequences of events in system accidents. We describe tools for scripting scenarios and mapping to a hybrid simulator. The generic component library of the simulator is used to construct component-connection models whose behavior can include a broad variety of types of performance problems and hazards. We illustrate the strategy with a design case with a biological water processing system.