Operational decision-making means controlling passenger demand, and allocating aircraft and other resources to work implied by demand. Accurate forecasting is then needed for making proper trade-offs between spoilage and rejects. Efforts towards implementing optimisation systems for airline operational problems have been in process for some twenty years. Departure overbooking was one of the first successful implementations in Scandinavian Airlines. Several attempts to use traffic forecasts in operational resource planning systems have been successful. One key issue has been the need to quantify the airline strategy when optimising in a functional planning situation. Several application examples are given.