To ensure a robust mass production, the automotive industry relies on computer aided tolerancing to guarantee the dimensional quality of the vehicles' body-in-white. One of the challenges for computer aided tolerancing is the accurate modelling of the positioning for joining processes in the body-in-white production. The research work presented in this paper analyses three use-cases, on which different approaches of modelling of the so-called geo-stations are investigated, aiming at improving the deviation prediction based on the geo-station modelling. The examples show that the measurement values are met most accurately, if the positioning processes of the geo-station are taken into account as the dominant impact factor in the simulation.