This volume contains selected papers presented at the International Conference on Operations Research SOR 2002 held at the University of Klagenfurt from Sep� tember 2 to September 5, 2002. The conference was organized under the auspices of the German, the Swiss and the Austrian Operations Research societies - Gesellschaft fiir Operations Research e.V. (GOR) - Schweizerische Vereinigung fiirOperations Research (SVOR) - Osterreichische Gesellschaft fiirOperations Research (OGOR). After Vienna (1990), Berlin (1994) and Ziirich (1998) this has been the fourth time that the three societies organized ajoint conference. The conference was attended by more than 400 participants from countries all over the world which demonstrates the broad interest in all aspects ofOperations Research. The scientific program of the conference consisted of 4 plenary lectures, 5 semi plenary lectures, and about 320 contributed papers which have been presented in 16 sections. Due to the limited number of pages available for the proceedings vol� ume, the length of each article as well as the total number ofcontributions had to be restricted. The decision on the acceptance of papers for the proceedings has been made in close eo operation with the section chairmen and was based on their suggestions. We wish to express our sincere thanks to the chairmen for supporting our editorial work by refereeing the manuscripts and letting us have their advice. We also would like to thank Dr. Wemer Muller from Springer-Verlag for his support in publishing this proceedings volume so quickly.