The CRM, IVADO, and GERAD organized jointly the Fifteenth Montreal Industrial Problem Solving Workshop, which was held at HEC Montréal on June 2-6, 2025. We wish to thank our faithful partners, particularly Air Canada and the National Bank of Canada, for submitting problems to the workshop. We are also grateful to the professors who coordinated the work of the teams, namely Janosch Ortmann, Ting-Huei Chen, Rafael Cruz, and Gilles Caporossi.