I Acknowledgment I want to thank to Ph.D. Acácio Galhardo for the great willingness to accept me as my I.S.E.L. tutor. I want to thanks also to Prof. Ricardo Luis, for guide me in the Erasmus process. Thank you for all your efforts. I specially want to thank to my German tutor, Dipl.-Ingenieur Raphael Buck, for all the help he gave me and most of all for never make me feel I was alone. Another special thanks to Harro Höfliger team. They always make me feel like I was at home, and most of all they had so many patience speaking to me always in English because they know in that time my German was not so good. They are Mr. Scheub, Mr. Weller and Mr. Haupt from development department. I only have good memories from them. Special thanks for my friend and college Rui Figueiredo for all the friendship and company he gave to me, after all, we are the only two Portuguese in the Stuttgart University Campus. Finally, I want to most specially thanks to my parents and my girlfriend, Carla, for all the