This current thesis is about the issue of small-scale, locally situated failures in globally stabilized slopes by wire netting, wire rope nets and anchors. The load caused by these failures acts on the assembly of nets and anchor rods. A failure model is created, that simulates the failure between two layers of anchors. The mobilized soil body due to this failure acts as a load on the support system. It is based on the well known method of Fellenius, which simulates failure along a circular sliding surface. This failure model is evaluated by both model tests as well as numerical studies. Correlations between the findings of the base friction models, which are processed by Particle Image Velocimetry, and the failure model show similar failure geometry, whereas the findings of the numerical studies using the computer programs Slide and Plaxis do not show the same effects in all the tests. Less steep slopes show local failure that can be associated with the failure model, whereas in steeper models these effects are overlayed by the global instability. Subsequently a comparison between the mobilized volumes due to the failure model and the base friction tests is made.The comparison shows a good correlation.