Airport decision makers face frequently complex decisions related to airport planning, design, and operations. These decisions are highly complicated since they involve a variety of entities processed through the system, a number of different airport elements, and a large variety of airport performance measures such as capacity, delays, safety, security, noise, and cost-effectiveness. Existing airport modeling capabilities suffer from (a) fragmentation between the various airport elements, entities, and their operations; (b) the isolated manner in which the airport performance measures are assessed and modeled; and (c) the lack of user-friendly modeling capabilities and decision support systems adopting a problem-oriented approach for airport decision making and planning. Advanced airport modeling capabilities should be deployed to integrate domain knowledge with tool expertise in assisting airport decision makers to answer frequently arising airport planning questions in an integrated, user-friendly, and problem-oriented environment. The operational concept for an integrated, problem-oriented modeling approach for total airport performance analysis is introduced, the development of a decision support system for airport performance assessment and capacity management is described, and the modeling and decision support capabilities of the system are demonstrated.