Synchronous blade vibrations can have a severe impact on the service life of rotors as their occurrence leads to limit cycle oscillations, which over time increase the risk of component failure due to high cycle fatigue. A property that can substantially influ- ence the vibration characteristics of the rotor is mistuning. Mistuning appears due to structural differences between the blades, which violates the rotational periodicity of the impeller. Manufacturing tolerances, material inhomogeneities and uneven wear of the blades during operation are the main causing factors. Mistuning leads to localized dissipation of the vibration energy and significant amplitude overshoots. As a result, the amplitude of individual blades can be significantly higher than those of rotationally pe- riodic structures.