Explaining and repairing plans that fail

摘要

A persistent problem in machine planning is that of repairing plans that fail. One approach to this problem that has been shown to be quite powerful is based on the idea that detailed descriptions of the causes of a failure can be used to decide between the different repairs that can be applied.This paper presents an approach to repair in which plan failures are described in terms of causal explanations of why they occurred. These domain-level explanations are used to access abstract repair strategies, which are then used to make specific changes to the faulty plans. The approach is demonstrated using examples from CHEF, a case-based planner that creates and debugs plans in the domain of Szechwan cooking.While the approach discussed here is examined in terms of actual plan failures, this technique can also be used in the repair of plans that are discovered to be faulty prior to their actual running.