The underlying Earth system and socio-economic system components of GEOSS are strongly interlinked forming a "fine" (complex) dynamic system. In order to quantify the total system benefit of GEOSS there was developed a dynamic computer simulation model called 'FeliX (Full of Economic-Environment Linkages and Integration dX/dt). The studies focus on exploring economic and environmental linkages and interrelations within and between specific Social Benefits Areas (SBAs), and measuring benefits of Global Earth Observation (GEO) across such defined systems. The model aggregates findings from particular case studies conducted as a part of the GEO-BENE project in particular SBAs. It maps in an explicit manner important elements of complex ecosystem. The simulation conducted in a dedicated, user-friendly simulator allows for analysis of the impact of GEO and for testing various scenarios and policies. Although the total system benefit is strongly policy scenario dependent we find that the total system benefits across all SBAs exceed the costs of the respective GEOSS.