Plan Diagnosis and Agent Diagnosis in Multi-Agent Systems
Roberto Micalizio and Pietro Torasso
The 10th Congress of the Italian Association for Artificial Intelligence (AIIA 2007)
Roma, Italy, September 10-13, 2007
Abstract
The paper discusses a distributed approach for monitoring and diagnosing the execution of a plan, where concurrent actions are performed by a team of cooperating agents. The paper extends the notion of plan diagnosis, introduced by Roos et al for the execution of a multi-agent plan, with the notion of agent diagnosis. While plan diagnosis is able to capture the distinction between primary and secondary failures, the agent diagnosis makes apparent the actual health status of the agents. The agent and the plan diagnosis are important pieces of information, which can be exploited during the process of plan recovery from an action failure. The paper presents a mechanism of failure propagation which captures the interplay between agent diagnosis and plan diagnosis; this mechanism plays a critical role in the understanding at what extent a fault affecting the functionalities of an agent affects the global plan too. In the monitoring and diagnostic steps, the system makes use of a relational model of the actions for capturing both the nominal and the abnormal result of their execution.