[Table of Contents]
[Abstract, english version]
My mentor, Prof. Dr. W. Gerhardt for approving this research topic, for copious technical discussions and for helping in the more administrative aspects of a promotion.
The members of the commission: Prof. dr. ir. P. Dewilde, Prof. dr. H. Koppelaar, Prof. dr. ir. F. Rammig, Dr. ir. R. van Leuken, and Dr. ir. P. van den Hamer for reading and correcting the concept version of this thesis.
My manager at GMD, Mrs. E. Abel, for making this research possible.
Dr. M. Sim, for initiating the contact with Prof. Gerhardt and lively discussing early ideas about the subject of tool encapsulation.
Dr. P. van der Wolf for discussing alternative approaches to extending the Nelsis schema and for giving me insight into the Nelsis messaging interface.
My colleagues at GMD, in particular A. Bredenfeld, R. Czech, S. Heymann, and A. Rockenberg for reading and discussing various versions of this thesis.
S. Heymann, for continuously encouraging me that tool encapsulation is in fact important.
The system administrators at the SET institute of GMD, R. Czech and B. Schwarz, for maintaining such a superb work environment.
D. Marckwardt, for proof-reading my English.
My employer, A. Audi, for tolerating my continuous work on the topic of this thesis, yet unrelated to his business.
My wife, Birgit, for her patience.