This paper gives a short summary of the corresponding poster session. The ESA Galileo System Simulation Facility (GSSF) is a simulation environment that reproduces the functional and performance behaviour of the Galileo system to support the simulation needs during the entire Galileo programme lifecycle. It is capable of simulating, besides the nominal system, also its various degraded modes, in a deterministic or probabilistic manner. The Space Segment and User Segment are not limited to Galileo and provide GPS and EGNOS related simulation models, and support also user-defined satellites and user-defined satellite constellations. The focus of this paper is to give examples on the uses and benefits of GSSF. Therefore short descriptions of the main GSSF analysis capabilities are given followed by numerous applications of GSSF in system analysis and application development.