The increase in the types of airspace users (large aircraft, small and regional jets, very light jets, unmanned aerial vehicles, etc.), as well as the very limited number of future new airport development projects are some of the factors that will characterize the next decades in air transportation. These factors, associated with a persistent growth in air traffic will worsen the current gridlock situation experienced at some major airports. As airports are becoming the major capacity bottleneck to continued growth in air traffic, it is therefore primordial to make the most efficient use of the current, and very often, underutilized airport infrastructure. This research thus proposes to address the increase in air traffic demand and resulting capacity issues by considering the implementation of operational concepts and technologies at underutilized airports. However, there are many challenges associated with sustaining the development of this type of airports. First, the need to synchronize evolving technologies with airports' needs and investment capabilities is paramount. Additionally, it was observed that the evolution of secondary airports, and their needs, is tightly linked to the environment in which they operate. In particular, sensitivity of airports to changes in the dynamics of their environment is important, therefore requiring that the factors that drive the need for capacity expansion be identified and characterized. Finally, the difficulty to evaluate risk and make financially viable decisions, particularly when investing in new technologies, cannot be ignored. This work thus focuses on the development of a methodology to address these challenges and ensure the sustainability of airport capacity-enhancement investments in a continuously changing environment. The four-step process developed in this research leverages the benefits yielded by impact assessment techniques, system dynamics modeling, and real options analysis to 1) provide the decision maker with a rigorous, structured, and traceable process for technology selection, 2) assess the combined impact of interrelated technologies, 3) support the translation of technology impact factors into airport performance indicators, and help identify the factors that drive the need for capacity expansion, and finally 4) enable the quantitative assessment of the strategic value of embedding flexibility in the formulation of technology portfolios and investment options. The proposed methodology demonstrates, through a change in demand at the airport modeled, the importance of being able to weigh both the technological and strategic performance of the technology portfolios considered. Hence, by capturing the time dimension and technology causality impacts in technology portfolio selection, this work helps identify key technologies or technology groupings, and assess their performance on airport metrics. By embedding flexibility in the formulation of investment scenarios, it provides the decision maker with a more accurate picture of the options available to him, as well as the time and sequence under which these should be exercised.