The Workshop is organized by 3 research centers: CMAFcIO, the MOSAIC group of CEG-IST and CEMAPRE. This Workshop will will occur in an online format and gather specialists in the field of Combinatorial Optimization, from several countries, to present and discuss recent research work around this subject. Luís Gouveia, coordinator of CMAFcIO, José Rui Figueira, coordinator of the MOSAIC group of CEG-IST, and João Janela from CEMAPRE will present the Opening Session.