This article formalises the dual problem to model-based diagnosis (MBD), i.e., generating tests to isolate multiple simultaneous faults. Using a standard propositional MBD framework, we first define a test of minimal size that can isolate multiple simultaneous faults of an arbitrary nature. Second, we prove complexity results for multiplefault tests of minimal size in propositional system models, showing such problems have complexity similar to those of MBD problems, i.e., complexity at the second level of the polynomial hierarchy.
Gregory M. Provan