Diagnosis of Plan Structure Violations

Failures in plan execution can be attributed to errors in the execution of plan steps or violations of the plan structure. The structure of a plan prescribes which actions have to be performed and which precedence constraints between them have to be respected. Especially in multi-agent environments violations of plan structure might easily occur as the consequence of synchronization errors. While in previous work we have concentrated on the first type of failures, in this paper we introduce the idea of diagnosing plan structure violations. Using a formal framework for plan diagnosis, we describe how Model-Based Diagnosis can applied to identify these violations of plan structure specifications and we analyze their computational complexity.