Using Scripts for Reactive Planning

We describe a model-based representation for real-time planning in technical processes. This means a complete model of causal and temporal dependencies is developed for an application. The main difference to other planners is that scripts, an event-oriented representation formalism is used and that goals and actions are part of the knowledge base in order to reason about old goals and already scheduled actions. Usually, model-based representations are object-centered structures with constraints between them. However, processes and events are more important in many technical applications than objects. The changes in physical or chemical processes have to be represented adequately. Knowledge about processes with uncertain durations that occur simultaneously must be represented. Moreover, knowledge about the past and the present that is definite has to be distin guished from knowledge about the future that may be hypothetical or imperative like scheduled actions or goals.