This paper discusses a new approach to the assessment of damage in structural steel components under cyclic inelastic loading stories of the type experienced in earthquakes. The approach is based on a new damage model proposed by the author. It is shown that the seismic performance of a steel component depends on two structural performance parameters: b and m. The parameter b is influenced by the material properties, the prevailing loading condition and the geometry of the steel component. The parameter m reflects the influence of the structural system, hysteretic behavior and characteristics of the earthquake. This approach takes into account that the cumulative damage—in addition to being affected by the total amount of dissipated energy, the maximum deformation and the number and amplitude of the cycles of deformation—is also path-dependent.