Fracture mechanics models can describe complex material behavior in a simplified manner. With their help, for example, predictions can be made about the crack growth and failure behavior of engineering-relevant materials. Such a model (cf. Lawn et al.) describes the crack behavior of 3-dimensional crack systems (so-called cone cracks) in brittle materials (e.g. glass) and enables the identification of the time of failure. The model was validated for a cone crack under bending load. The aim of the work is to first implement this model in a suitable programming language (Python, Matlab) or FEM software and then to investigate sensitivity analyses with regard to the reduction in strength for the various parameters (crack propagation angle, additional load, etc.).