The aim of this thesis project was to investigate the further development of an airport Decision Support Suite (DSS) - the Airport Business Suite (ABS). A financial model was developed and implemented by incorporating new approaches and methodologies to Airport Strategic Planning, with various financial guidelines and practices suggested by aviation authorities, and commonly accepted financial accounting methods. The resulting program allows for financial modelling of standalone years, while the more advanced functionality of being able to model an airport's financial performance over a number of years was limited to a Spreadsheet Model. The proposed model was found to produce satisfactory results. The aim was not to produce results with a high degree of accuracy (since the forecast is always wrong), but rather to model a number of generic relationships which could be applied to any airport or situation, which would allow the user to quickly explore the financial effects of various policy options and assumptions.