(86c) Design Optimization Using Automated Fta Tools

Making safety an integral part of a design as it is being developed rather than an activity that is applied at specific design "freeze" points is the focus of this paper. The conceptual work process and tools used to optimize a design from a safety/reliability perspective as it is being developed are discussed. By identifying design options in the early design stage and evaluating for the best option, the design can be optimized from a safety perspective and later safety add-ons reduced or eliminated. Complex designs often challenge ruled based design guidelines. Logical decisions for optimizing a system without actually evaluating it may in fact be the wrong decision. The results from fault tree analysis can be counter-intuitive and significant and clearly demonstrate this is a value added activity. Several examples of this interactive design approach and the tools used to accomplish it are included. The applications use a visual Basic type of graphical interface linked to fault tree software via DLL (dynamic link library) files. Users of FaultTree+ have been developing programs to allow analysts and designers to easily determine the probabilitstic implications of different design configurations and operating conditions in various combinations for the entire range of scenarios in chemical, nuclear power plant and aerospace applications. These efforts enable a reduction in the time and effort required to evaluate the safety of design options and system upgrades. Any new design or design upgrade would benefit greatly from using these cutting-edge risk tools.