Maria Fox and Derek Long
The International Planning Competitions, run by Drew Mc- Dermott in 1998 and Fahiem Bacchus in 2000, have provided an important spur to the planning community, encouraging the development of planning technology and of a wide selection of planning bench mark domains. One of the most important contributions has been the introduction of a widely accepted standard for domain description, Drew McDermott’s PDDL language (McDermott 2000), leading to the sharing of domains and planning systems. An equally important outcome, which has been extremely beneficial to the community, has been that planning research has made rapid progress in the four years since the competitions began and has risen to many interesting challenges. A complaint that has been often levelled at competitions in various research communities (theorem proving, natural language understanding, etc.,) is that they have tended to encourage a focus on winning for its own sake, rather than on tackling real problems that might have longer term interest for application. Competitions can have the negative effect of turning developers’ attention inwards so that systems are honed on artificial benchmark problems at which they can excel, rather than extended to meet real challenges. A consequence of this is that potential participants can be put off taking part in the competition if their technology is not tailored for efficient solution of such problems. The community is at risk of being deprived of seeing exciting and adventurous new developments whilst simple and unscaleable approaches occupy the limelight. Although this has not yet become a serious issue for the planning competitions it is a real danger and it is important to anticipate the danger and try to ensure that the competition remains relevant to the wider planning community. With these points in mind we decided to focus the 2002 competition on planning with temporal and metric domains. It is generally agreed that temporal modelling and reasoning is essential for the application of planning to practical problems, and certain high-profile application areas, such as space and aerospace applications, have encouraged developers to turn their attention towards these issues. Although some developers have already considered the management of temporal constraints in their planning systems this has not been widespread and there has been little agreement over the modelling of time. Certainly there have been no commonly accepted standards for modelling temporal planning domains and no temporal bench mark problems. This document briefly introduces the objectives of the 2002 competition and the extensions we have made to PDDL to support temporal modelling. Finally, we outline the structure of the competition, in terms of the tracks being run and the domains being considered in those tracks.