A general framework of constraint propagation for diagnostic systems

A general framework of constraint propagation that can effectively be used in model-based diagnostic systems is proposed. The framework is based on making a clear distinction between the global propagation mechanism that controls the propagation process as a whole and the local updating procedures that transmit values and reason sets through each constraint. A diagnostic expert system for combinational circuits that is based on this idea is presented. The system shows a good tradeoff between efficiency and generality and is believed to provide a basis for model-based diagnosis in other domains as well