The Chuquicamata open pit mine situated in Northern Chile is approaching the latter part of its surface mine life. With an excavated depth of close to 1000 m, maintenance of the pit slopes becomes increasingly challenging. One of the major controls on slope stability is the potential for large scale instabilities associated with major structures that can extend over hundreds of metres. Some of these major structures are mapped and included in mine planning models as wireframe surfaces. However there are a high number of structures that are large enough to cause significant instability, whilst being too small and numerous to explicitly model. With various options being considered for the end of life of the pit in terms of slope push back, slope steepening and ramp trimming, how could the impact of these major and intermediate structures be considered upon the outcome of the various design options? Discrete Fracture Network (DFN) modelling was identified as the most practical way to assess the potential for major kinematic instabilities as a consequence of movement upon major structures. Analysis of mapping, borehole and scanline geotechnical data, allows the spatial and geometrical properties of the fault network to be derived. Thus the large scale wireframed structures can be supplemented by intermediate scale stochastically generated faults that honour the same spatial and geometric patterns and properties. Of particular note was the fact that borehole fracture intensity data showed that fault intensity was strongly correlated to the distance to the nearest mapped major structures which enabled the distribution of stochastic intermediate faults to be controlled by a distance to fault property. In addition to using the DFN model to probabilistically evaluate the volume of unstable material as a consequence of the three different closure options, a novel technique was developed for mapping areas of the slope that were prone to block formation and therefore potential instability. This involved stacking the kinematic results of multiple realisations of where blocks had been found within the DFN at the slope level and computing the probability of occurrence of these blocks within a 3D grid of the pit slope. The result being risk maps of kinematic block formation across the pit surface.