To significantly improve manufacturing processes, the intrinsic geometric deviations of machine tool must be optimized. Despite the international standard ISO 230-1, many geometric errors model are developed in the literature. In this paper, the modeling of a RRTTT five-axis machine tool including geometric error related to the international standard is carried out. The reduction and determination of model parameters is based on a combinatorial analysis coupled with rank analysis. The goal is to find all groups of position and orientation axes errors to model the volumetric accuracy actually measured. This task is performed by probing a datum sphere with a touch probe integrated in the machine tool. Finally, a combination of optimal parameters is determined in order to better map volumetric accuracy.