Mohamed works on developing efficient methods for solving hard problems. For example, how can one use limited resources to complete a series of tasks in an optimal way? The problems that we face when dealing with real world situations are often complex to manage. The usage of a modular, flexible, and efficient approach is extremely beneficial to tackle these situations. Constraint programming (a system for supporting decision making in scenarios where there are lots of variables, such as scheduling surgical procedures in a hospital) answers perfectly these needs. Mohamed developed many techniques in constraint programming to solve a number of combinatorial problems such as scheduling, sequencing, and matching under preferences. These solutions are often based on hybrid methods coming from artificial intelligence, Boolean satisfiability, and operational research.