Development of Combined Performance and Dependability Analysis Tools for Flight Critical Avionic Systems

摘要

The object of this SBIR Phase I research is to develop fault tolerance analysis tools for flight critical avionic systems. The report demonstrates the feasibility of integrated performance and dependability modeling, a need that has not been adequately met. Evaluation metrics were developed and representative performance/dependability modeling tools were evaluated through case studies. The evaluation identified two approaches that can overcome the 'time explosion' problem encountered in modeling performance (high occurrence rate) and dependability (very low occurrence rate) events: (1) combining discrete event performance simulation and analytical dependability modeling, and (2) fault injection simulation with importance sampling, The report shows how to relate performance measures (system capacity) to system states in terms of component failures in implementing the first approach. The 'performance loss' measure is introduced and the likelihood ratio for this measure is generated to support the second approach. To automate these approaches, a tool set that integrates a commercial performance simulation tool and a commercial dependability modeling tool is proposed. Necessary improvements/extensions to these tools are identified. The proposed tool set is suitable for military avionic systems as well as commercial fault tolerant systems.