In spite of the fact that there is just one name on the cover, the work collected here is obviously the result of a combined effort by several people. There are some persons I would like to thank for their personal contributions to what has been written down in this dissertation.
First of all I want to thank my supervisor Gccrt Jan Olsder for his introduction to the area of Discrete Event Dynamic Systems and, more specifically, the approach of max-plus algebra. It was during his course, given for the Dutch Graduate School of Systems and Control, that his enthusiasm quickly made me interested in this subject. When the possibility arose to start research in this area I did not hesitate. I am grateful to Geert Jan for his guidance during the four years of the research project.