At the beginning of the year 2019 the European Terrestrial Reference System 1989 will be established in Bavaria as authoritative coordinate system for the cadastre and for the geotopography. The Spatial Reference System of the Authoritative Real Estate Cadastre Information System ALKIS will change simultaneously to ETRS89/UTM. For the transformation of different cadastral feature type groups of ALKIS the Bavarian National Mapping Agency for Digitisation, High-Speed Internet and Surveying has developed the transformation approach Ortra, which uses least-squares adjustment techniques. The Ortra adjustment model furthermore possesses elasto-mechanical analogies. For the transformation, the necessary geodetic network constructed of pseudo-observations with orthogonal elements is in the state of equilibrium and therefore subject to mechanical laws like the theorem of least work. The preservation of neighborhood accuracy from GK to UTM by least work and the reduction of net distortions results in a homogenization of data during the transformation process to the European system ETRS89. The paper presents the fundamentals of the ortra approach. By means of laws of mechanics it is discussed how the Ortra approach preserves the geometry in the presence of net distortions. Finally, it will be shown for the hierarchical network approach of Ortra, how coordinate discrepancies, which are caused by net distortions, are distributed.