The planning process in scheduled passenger traffic is a very complex task and many decisions in the planning process have to be fixed under uncertainty. In long-term planning airlines and public transport companies have to cope with demand and fuel price uncertainty, for example. In short-term planning unforeseeable disruptions due to weather conditions or traffic density cause deviations from the plan. As a result, the profit of companies operating in scheduled passenger traffic highly depends on the development of uncertain parameters. To manage and limit the risk of bad scenarios, more robust plans have to be created. The robustness of the plans can be increased by integrating risk management into the planning process. The risks can be decreased with operational methods, such as changing the aircraft type of a flight or increasing the buffer time between two bus trips, as well as with contractual methods, such as hedging fuel prices. The objective is to find more robust solutions for the planning process in scheduled passenger traffic. Existing optimization models are re-developed or new models are developed from scratch, an integrated risk management strategy is integrated into these models, and case studies are used to show the advantages for robust planning.