A Framework for Decentralized Qualitative Model-Based Diagnosis (preliminary report)

In this paper we propose a framework for decentralized model-based diagnosis of complex systems. We consider the case where subsystems are developed independently along with their associated (or embedded) software modules - in particular their diagnostic software. This is useful in those situations where subsystems are developed (possibly by different suppliers) without a-priori knowledge of the system in which they will be exploited, or without making assumptions on the role they will play in such system. We describe a decentralized architecture where subsystems are analyzed by Local Diagnosers, coordinated by a Supervisor. Within the framework, both the Local Diagnosers and the Supervisor can be designed independently of each other, without any advance information on how the subsystems will be connected (provided that they share a common modeling ontology) and allowing also for runtime changes in the overall system structure. Local diagnosers are thus loosely coupled and communicate with the Supervisor via a standard interface, supporting independent implementations.