Rapidly increasing congestion and delays have put serious pressure towards close airport performance monitoring. Airport decision makers should be able to cope with multiple – even conflicting – objectives and priorities assigned by various stakeholders. The assessment of the airport performance requires a deep understanding of the manifold performance aspects supported by advanced modelling capabilities. A wealth of decision support models and tools have appeared in both literature and practice, however, most addressed only partial aspects of the airport performance and exhibited several deficiencies with the most important being the clear lack of integrated modelling capabilities. This chapter presents the development of a system (SPADE) that will not only capture the manifold aspects of airport performance, but will also deploy a decision-oriented approach capable of analysing at a reasonable effort and at various levels of detail (e.g. strategic, tactical) the trade-offs among airport performance measures, entities, or elements. The objective of this chapter is twofold: (1) to introduce the structure and constituting elements of the SPADE system and (2) to demonstrate its decision support capabilities under ‘real-world’ conditions by means of two applications for strategic (Athens International Airport) and operational/tactical decision making (Amsterdam Airport Schiphol).