On behalf of EngOpt organizing committee we are pleased to welcome you to Lisbon for the 6th International Conference on Engineering Optimization held at Instituto Superior Técnico of the Universidade de Lisboa.The main goal of EngOpt conference series is to periodically bring together engineers, applied mathematicians and computer scientists working on research, development and practical application of optimization methods applied to all engineering disciplines or developing basic techniques in this field. Following the very successful conference in Foz do Iguassu, Brasil (EngOpt2016), the 6th International Conference on Engineering Optimization (EngOpt2018) is now held in Lisbon. The purpose of this Conference is to provide opportunities for scientists and engineers to meet and to discuss current research, new concepts and ideas and establish opportunities for future collaborations in all aspects of Engineering Optimization. We invite you to be an active participant in this Conference and to contribute to any topic, or mini-symposium, of your scientific interest. By promoting a relaxed atmosphere for discussion and exchange of ideas we expect that new paths for research are stimulated and promoted and that new collaborations can be fostered. We hope that the 6th International Conference on Engineering Optimization will have an important impact on the research in all topics included in its programme. We want to express our appreciation to all members of the committees involved in the preparation of this Conference, to all mini-symposia organizers who identified and promoted some of the most active topics of research in Engineering Optimization, to all the staff who are managing the different aspects of the Conference and to all the contributing authors and participants who will create the real Conference. We hope that all of you feel rewarded for your participation and contribution.

Sincerely Yours, Hélder Rodrigues, IST, IDMEC (EngOpt2018 Chairman) José Herskovits, COPPE/UFRJ (EngOpt2018 Co-Chairman) Cristóvão Mota Soares, IST, IDMEC (EngOpt2018 Co-Chairman)