Electrical Engineering not only deals with dynamics and strength but also with operability analysis. The most frequent structures we take care of are switch gear cabinets and also of electric motors and generators in manifold versions with regard to constructive design and equipment. Stability proofs are normally realized by means of calculative simulation via finite-elements-models. Simple proofs of functionability via deformation parameters are also realized calculationally. In case of complex components we carry out experimental proofs of functionability by means of vibration tests. Other than regular operating loads we also deal with special loads of external events, for example earthquakes.