Distributed goal-directed dynamic plan revision

We contrast in this article the system demands imposed by brute force, complete replanning and a new, goal-directed approach called dynamic plan revision (DPR). One of the two processes must be invoked when some aspects of the environment change and currently existing plans are likely to fail. Complete replanning is conceptually simpler but requires significantly more computation because it reproduces also those plan steps that have not been affected by the changes. DPR attempts to minimize the scope of replanning and makes to the current plans as small amount of modification as possible. The more rapidly the environment changes, the less practical complete replanning becomes. The issue is even more significant with time-critical applications. DPR uses goal hierarchies produced at the same time when plans are generated. The planning systems has an "active attitude" toward the feedback from the environment and takes advantage of all information becoming available during plan execution. We have also developed and implemented a distributed version of this approach in the domain of Distributed Manufacturing Operations12,13. The relevant algorithms are given in the Appendices A and B.