Simulation-based testability analysis and fault diagnosis

In the past, system-level testability analysis and fault diagnosis have been largely based an either structure or manual cause-effect analysis (e.g. qualitative models, dependency models, multi-signal models, signed directed graphs). This process is time-consuming. This paper proposes a general methodology for automatically extracting multi-signal diagnostic inference models of systems via fault-simulation of design descriptions. Specifically it addresses the problem of generating inference models of digital/analog circuits and complex functional blocks (e.g. servo mechanisms, process control systems, flight control systems) for system-level testability analysis and fault diagnosis. The proposed method: (1) ensures a detailed failure-modes and effects analysis of systems, (2) automatically defines tests with well-defined stimuli, observations and test limits, (3) creates an efficient and intuitive test strategy by using test precedences and test levels, and (4) eases the process of inference model verification