(eng): This special issue is dedicated to Lluís Godo in the occasion of his 60th anniversary. Lluís is a man with solid academic foundations. He studied Mathematics at the University of Barcelona and Industrial Engineering at the Technical University of Catalonia, and throughout his academic life, he has been loyal to both traditions: the purely scientific and the applied. Even though he has published numerous theoretical works, he never shied away from finding how to model and solve a practical problem.