The excitation from the tooth mesh can be seen as main reason for the noise and vibration behavior of a gearing. This excitation is decisively influenced by the gear geometry. That includes macro geometry as well as tooth flank modifications. In many cases the design of flank modifications needs to meet the requirements of high bearing strength and low excitation level. Furthermore dynamic effects (e.g. resonance behavior) are important for the excitation level of a gearing, especially for operation at variable speed. The software DZP ("Dynamic tooth force program") covers a wide range of computation in the field of gear excitation and dynamics.