Error recovery: a condition-oriented replanning approach

Normally, a plan must be carried out in a world whose behavior cannot be predicted exactly, so that failures (or unexpected events) can occur during execution. A system that is capable of handling such failures is presented. The error recovery process consists of error detection, error identification, and plan repair. The problem of error identification has been solved by using the condition-oriented approach, which is the authors´ central theme. Error classification is accomplished by checking the role of failed conditions in the plan. If all conditions in a plan are stored during the plan generation phase, the subplans that are affected by a failed condition can be easily located. Three error categories and the modification processes are described