The present dissertation is testimony that sometimes the choice of a difficult path can be more enriching and that all the effort will be rewarded by the accomplishment of the defined objectives, reason why it is necessary to express the sincere thanks and gratitude inherent in this process. Firstly, I would like to thank my mentors, Professor Vítor Braga and Professor Eliana Costa e Silva, for all the guidance, constructive criticism, dedication and effort, applied in the various moments to accomplish objectives, deadlines and dynamize this dissertation in a more correct and comprehensive way. A special recognition for all the hours spent in search of results, studies and sharing of knowledge, as well as for all the commitment made with me to the realization of it. Next, I would like to thank the Escola Superior de Tecnologia e Gestão, responsible for my training throughout the academic course and the Research Centre, for the availability of tools and opportunity to participate in events that allowed the dissemination of this work. To my parents, thank you for your work over the years, for always believed in me, for the affection and for making available all the resources so that nothing was lacking in me at educational level, and at all other levels, encouraging me every day and putting hope in every conquest or obstacle. To Pedro, I would like to thank you for your fellowship and your patience throughout this academic journey. For the support, love and for being tireless to motivate me, to never give up my goals and to collaborate with me in any situation, keeping the worries away. Also, a special thanks to Vera, who even with the rush of everyday life, made available to support me in the realization of this dissertation. Thanks to all the wonderful people who have been with me during this academic journey, this experience has become even more significant and rewarding on a personal and professional level, and without a doubt it will be on your side that another victory will be celebrated. To all I express my sincere gratitude.