Theory Diagnoses: A Concise Characterization of Faulty Systems

Gerhard Friedrich

Abstract: In this article a new characterization of the set of diagnoses in the domain of consistency-based diagnosis is developed. The needs for such a characterization arise from the inability of the current characterizations (e.g. minimal diagnoses and kernel diagnoses) to deal with abstractions like component hierarchies. We propose a characterization based on theories which takes advantage of hierarchies and therefore allows a concise description of various sets of diagnoses (e.g. minimal diagnoses and kernel diagnoses). We investigate a concise description of the set of all minimal diagnoses in detail and focus on hierarchical theories. Finally, we show that theory-based diagnoses and hierarchical theories provide efficient generators for computing minimal diagnoses.