Planning with External Events
This addresses planning problems in uncertain domains, but it appears incremental as it builds on existing probabilistic planning techniques.
The paper tackles planning under uncertainty from external events by introducing a goal-directed, backward-chaining planner that uses Bayesian belief nets to compute plan success probabilities, with Monte Carlo simulation and Markov chain methods to reduce computational costs.
I describe a planning methodology for domains with uncertainty in the form of external events that are not completely predictable. The events are represented by enabling conditions and probabilities of occurrence. The planner is goal-directed and backward chaining, but the subgoals are suggested by analyzing the probability of success of the partial plan rather than being simply the open conditions of the operators in the plan. The partial plan is represented as a Bayesian belief net to compute its probability of success. Since calculating the probability of success of a plan can be very expensive I introduce two other techniques for computing it, one that uses Monte Carlo simulation to estimate it and one based on a Markov chain representation that uses knowledge about the dependencies between the predicates describing the domain.