TheEuropeanConferencesonPlanning(ECP)areamajorforumforthepres- tation of new research in Arti?cial Intelligence Planning and Scheduling. They developed from a series of European workshops and became successfully es- blished as international meetings. Previous conferences took place in St. Au- stin (Germany) in 1991, Vadstena (Sweden) in 1993, Assisi (Italy) in 1995, and Toulouse (France) in 1997. ECP-99 was held in Durham, United Kingdom. The conference received s- missions from all over Europe, from the US, Canada, South America, and New Zealand. This volume contains the 27 papers that were presented at the conference. They cover a variety of aspects in current AI Planning and Scheduling. Several p- minent planning paradigms are represented, including planning as satis?ability andothermodelcheckingstrategies,planningasheuristicstate-spacesearch,and Graphplan-Based approaches. Moreover, various new scheduling approaches and combinations of planning and scheduling methods are introduced. Inadditiontotheconferencepapers,threeinvitedtalkswerepresentedbydist- guished researchers of the ?eld: Fausto Giunchiglia (IRST Trento, Italy) gave an introduction to Planning as Model Checking.
The corresponding paper by F- sto Giunchiglia and Paolo Traverso is included in this volume. Claude Le Pape (BouyguesTelecom,France)presentedConstraint-BasedScheduling:Theoryand Applications, and Nicola Muscettola (NASA Ames, USA) talked aboutPlanning at 96 Million Kilometers from Earth. ECP-99 received support fromPLANET,the European Network of Excellence in AI Planning, the University of Durham, United Kingdom, and the University of Ulm, Germany.