Scheduling employees in Quebec's liquor stores with integer programming

The SAQ (in French, Société des alcools du Québec) is a public corporation of the Province of Quebec responsible for distributing and selling alcohol-based products in its territory through a large network of more than 400 stores and warehouses. Every week, the SAQ has to schedule more than 3,000 employees. Until 2002, it handled this process manually, incurring estimated expenses of $1,300,000 (CAN). I developed a solution engine that interacts with a Web-based database system developed in house to produce the desired schedules. This solution engine implements an integer-programming (IP) model using ILOG Concert Technology and solves the IP formulation with ILOG CPLEX. The project has contributed to increasing the efficiency of the organization by reducing the costs of producing the schedules and by improving the SAQ's management of human resources. Overall, the SAQ estimates that automated scheduling has saved over $1,000,000 (CAN) annually.