Paradoxes in planning

The word 'planner' has two distinct meanings in literature. The first meaning refers to the profession of a human. Organizational processes must be planned so people know what work they are going to do. An example is a production planner in a factory. The second meaning of planner refers to an actor who must think about his actions before performing them, for example making a shopping list. Both connotations of planner have their own research fields. The profession of the human planner is mainly analyzed in the context of computer support. Examples of research areas are knowledge acquisition, task modeling, decision support, constraint modeling and solving, and operations research. The second meaning of planning is dealt with, for example, by psychology, semiotics, Artificial Intelligence, and robotics. Apparently, both planning worlds have their own research methodologies, languages, ontologies, and models. In this article, we describe the main schools for both fields and the apparent paradoxes that are the result of integration. (C) 2001 Elsevier Science Ltd. All rights reserved.