This research project aims to model shared vehicle systems at strategic and tactical levels. The objective is to obtain a simple model that establishes the existing trade-offs between the agency costs (i.e. vehicle fleet, stations, repositioning costs) and the user costs (i.e. access and wait). This would allow optimizing the main strategic and tactic variables of the system (i.e. strategic: total number of vehicles, density of stations; tactic: size of each station, occupancy at each station after a complete rebalancing period).