Verifying plans for multiple agents

Research in distributed artificial intelligence planning has historically focused on two distinct classes of problems. One paradigm has been that of ‘planning for multiple agents’, which considers issues inherent in centrally directed multi-agent execution. The second paradigm has been ‘distributed planning’, where multiple agents more autonomously participate in coordinating and deciding upon their own actions. The work described in this paper is in the first category, planning for multiple agents. Taking the STRIPS representation of actions, and directed acrylic graphs (DAGs) as plan representations particularly well suited to parallel execution, it formally analyses the following question: how can a DAG plan be verified (i.e. how can we be sure such a plan will be correct, given our uncertainty about exactly when unconstrained parallel actions will be performed)? A method is presented for verifying the correctness of plans for multiple agents, represented as DAGs. The technique allows for the efficient analysis of a plan, despite its many potential execution histories.