This volume presents the proceedings of the thira German-Italian Symposium on the Applications of Mathematics in Industry and Technology sponsored mainly by the research foundations of Germany and Italy, DFG and CNR. We had not published the proceedings of the second symposium held in Germany, but are now convinced that a publication would be appreciated by many scientists. The aim we had in mind organizing this symposium and communicating its scientific content was essentially the same as in the previous symposia - we were led by the same scientific and cultural (maybe even political) ideas. The scientific idea is simple: Mathematics becomes a more and more important tool in technology, business and organisatio- but mathematics does not play a corresponding role. The reason is that neither the public opinion nor the mathematicians them- selves are really aware of this fact. To show the richness and efficiency of this "industrial raw material" mathematics - at least in some domains - was one subject of the conference. In planning the structure a decision had to be made: If one wishes to present a huge variety of applications of mathematics in very different fields, the participants may loose the track, cannot find any connection with their own field of research in too many lectures; the symposium des integrates like a puzzle into many pieces, which are not easy to be put together again.