The Twelfth Montreal IPSW took place on August 22-26, 2022, and was jointly organized by the Centre de recherches mathématiques (CRM) and the Institute for Data Valorization (IVADO). For the first time since 2019, the workshop was held "in person", after two virtual workshops held in 2020 and 2021, respectively. More than 80 persons registered for the workshop and studied eight problems, submitted by Air Canada, the National Bank of Canada, Beneva, Environment and Climate Change Canada, Hydro-Québec, IATA, Radio-Canada, and Revenu Québec.