This volume contains a selection of papers referring to lectures presented at the symposium ”OperationsResearch 2006” (OR 2006) held at the university of Karlsruhe, September 6 - 8, 2006. This international conference took place under the auspices of the Operations Research Societies of Germany (GOR), ¨ Austria (OGOR), and Switzerland (SVOR). The symposiumwas attended by morethan 600academicsand practiti- ers from 35 countries. It presented the state of the art in Operations Research and related areas in Economics, Mathematics, and Computer Science and demonstrated the broad applicability of its core themes, placing particular emphasis on Basel II, one of the most topical challenges of Operations - search. The scienti?c program consisted of two plenary talks, eleven semi-plenary talks and more than 400 contributed papers, selected by the program c- mittee and arranged in 19 sections. These presentations were complemented by the lectures of the GOR prize winners including the Unternehmenspreis, which has been awarded for the ?rst time. Firstofallwethankallparticipantsoftheconference,whosubmittedtheir paper for publication. However, due to a limited number of pages available for the proceedings volume, the total number of accepted papers had to be restricted. Moreover, we want to express our thanks to the program committee and the section chairs for their support in acquiring interesting contributions and acting as a referee. Finally, we thank Anna Palej for gathering and editing the accepted papers as well as Dr. Werner A. Muller ¨ and Barbara Feß from Springer for their support in publishing this volume.