The Operations Research and Discrete Optimization (ORDO) group investigates and develops mathematical models and optimization methods for tackling complex decision-making problems. The main research focus is the study and the solution of linear and nonlinear discrete optimization problems, with an emphasis on those related to graphs and networks. The areas of application range from telecommunications and transportation to data mining and health care management. The expertise is in: mathematical programming; design and analysis of exact, approximate and heuristic algorithms; combinatorial optimization; graph theory and computational complexity. Research is often motivated by important applications but simplified versions of the problems or abstractions are also investigated from a theoretical point of view.