The idea of this book came from Professor Petzow, during the PML Betriebsausflug in September 1991. In a very informal way Professor Petzow invited S. G. F. (who was ready to return to Brazil after two years working with H. L. Lukas) to help H. L. L. to collect all his ideas about, and experiences with, thermodynamic optimization and put them into a book. Work on optimizations has been going on at Stuttgart for a long time, and valuable experience has been accumulated. Dr Lukas' feeling for optimizations is very well defined and one can talk about a “Lukas school for optimizations.”

Later the project was enriched by the cooperation with Professor Sundman, at that time Dr. Sundman, who brought his own large experience on computational thermodynamics as well as the Stockholm group's approach to the theme with all the formalisms so well developed by Professor Mats Hillert.

The three authors were very motivated by the idea, since the lack of such a book had always made it difficult to introduce students and researchers to this field. The knowledge necessary in order to obtain a better thermodynamic description of a system is very broad, requiring a judgment of the experimental data provided by the literature and also a wise selection of the model best able to describe the experimental evidence. This judgment is difficult, but the better “educated” the assessor, the greater his ability to judge well.