Resource Loading by Branch-and-Price Techniques

Twente. Beta is the largest research centre in the Netherlands in the field of operations management in technology-intensive environments. The mission of Beta is to carry out fundamental and applied research on the analysis, design, and control of operational processes. Cover: branching of the Ohio river (satellite image) No part of this work may be reproduced by print, photocopy, or any other means without prior written permission of the publisher. Dit proefschrift is goedgekeurd door de promotoren: Voor mijn ouders en Hana vii Acknowledgements If you would not be forgotten, as soon as you are dead and rotten, either write things worthy reading, or do things worth the writing. When, during the final stage of my graduation at the Faculty of Applied Mathematics at the University of Twente in late 1996, Henk Zijm approached me to inquire whether I would be interested in becoming a Ph.D. student, I immediately told him that that was the last thing on my mind. At that time I was developing a mathematical model of the liberalized electricity market in Western Europe at the Energy Research Foundation (in Dutch: ECN). Although my interest in developing mathematical models and solution techniques was sparked, my image of Ph.D. students consisted of people spending all their time in dusty libraries doing research for four years. Henk quickly persuaded me. Looking back, nearly five years later, I am very glad I accepted the opportunity he offered. Many people contributed to this thesis. I thank them all. I like to thank the people below in particular. In the first place I express my gratitude to Henk for giving me the opportunity to work under his inspiring supervision. I have learned a lot from him, and his enthusiasm was always a great motivation. I consider myself very lucky to have had Noud Gademann as my supervisor. He has an amazing eye for detail, and an unremitting patience for repeatedly correcting my mistakes. Every meeting was a learnful experience, almost always yielding fruitful ideas. It has been most pleasant to work with him, and I hope we will be able to continue this in the coming years. I thank Steef van de Velde, whose idea of using branch-and-price techniques for resource loading problems formed the starting point for this research. Although we met less often after he transferred to the Erasmus University, his ideas and comments contributed a lot to this thesis. …