QAPLIB - A Quadratic Assignment Problem Library

The Quadratic Assignment Problem (QAP) has remained one of the great challenges in combinatorial optimization. It is still considered a computationally nontrivial task to solve modest size problems, say of size n = 20: The QAPLIB was rst published in 1991, in order to provide a uni ed testbed for QAP, accessible to the scienti c community. It consisted of virtually all QAP instances that were accessible to us at that time. Due to the continuing demand for these instances, and the strong feedback from many researchers, we provided a major update in 1994, which was also accessible through anonymous ftp. In this update we also included many new problem instances, generated by several researchers for their own testing purposes. Moreover, we included a list of current champions, i.e. best known feasible solutions, and best lower bounds. The current update re ects on one hand the big changes in electronic communication. It has become a World Wide Web site, the QAPLIB Home Page. The online version will be updated on a regular basis and also contains most of the currently best known permutations. On the other hand, we feel the update was necessary, due to the increased research activities around the QAP, carried out in the last years. Therefore we also include a short list of dissertations concerning QAP, which were written in the last few years.