Le diagnostic est la tâche consistant à déterminer si un système se comporte correctement et, dans le cas contraire, à identifier le composant défaillant ou le type de faute. En IA et en raisonnement automatisé, les méthodes de diagnostic utilisent les observations du comportement du système pour inférer les causes probables d’erreurs ou de dysfonctionnements.
Concerned with the development of algorithms and techniques that are able to determine whether the behaviour of a system is correct. If the system is not functioning correctly, the algorithm should be able to determine, as accurately as possible, which part of the system is failing, and which kind of fault it is facing. The computation is based on observations, which provide information on the current behaviour.