An integrated diagnostics virtual test bench for life cycle support

Qualtech Systems, Inc. (QSI) has developed an architecture that utilizes the existing TEAMS (Testability Engineering and Maintenance Systems) integrated tool set as the foundation to a computing environment for modeling and rigorous design analysis. This architecture is called a Virtual Test Bench (VTB) for Integrated Diagnostics. The VTB approach addresses design for testability, safety, and risk reduction because it provides an engineering environment to develop/provide: 1. Accurate, comprehensive, and graphical model based failure mode, effects and diagnostic analysis to understand failure modes, their propagation, effects, and ability of diagnostics to address these failure modes. 2. Optimization of diagnostic methods and test sequencing supporting the development of an effective mix of diagnostic methods. 3. Seamless integration from analysis, to run-time implementation, to maintenance process and life cycle support. undetected fault lists, ambiguity group lists, and optimized diagnostic trees. 4. A collaborative, widely distributed engineering environment to "ring-out" the design before it is built and flown. The VTB architecture offers an innovative solution in a COTS package for system/component modeling, design for safety, failure mode/effect analysis, testability engineering, and rigorous integration/testing of the IVHM (Integrated Vehicle Health Management) function with the rest of the vehicle. The VTB approach described in this paper will use the TEAMS software tool to generate detailed, accurate "failure" models of the design, assess the propagation of the failure mode effects, and determine the impact on safety, mission and support costs. It will generate FMECA, mission reliability assessments, incorporate the diagnostic and prognostic test designs, and perform testability analysis. Diagnostic functions of the VTB include fault detection and isolation metrics undetected fault lists, ambiguity group lists, and optimized diagnostic trees.