Improving fault diagnosis accuracy by automatic test set modification

Fault diagnosis is the task of identifying a faulty component in a complex system using data collecting from a test section. Diagnostic resolution, that is the ability to discriminate a faulty component in a set of possible candidates, is a property that the system model must expose to provide accuracy and robustness in the diagnosis. Such a property depends on the selection of an appropriate test set capable to provide a unique interpretation of the test outcomes. In this paper a quantitative metric for the evaluation of diagnostic resolution of a test set is proposed, together with an algorithm for the minimal extension of a given test set in order to provide a complete discrimination of failures affecting a system, to be used as a support for analysts during the definition of a testing framework.