This document describes a procedure for fatigue strength assessment based on cumulative damage of rail vehicle structures that are manufactured, operated and maintained in accordance with standards valid for rail system applications. This document is applicable for variable amplitude load data with total number of cycles higher than 10000 cycles. An endurance limit approach is outside the scope of this document. The assessment procedure is restricted to ferrous materials and aluminium. This document does not define design load cases. This document is not applicable for corrosive conditions or elevated temperature operation in the creep range. This document is applicable to all kinds of rail vehicles~ however it does not define in which cases a fatigue strength assessment using cumulative damage is to be applied.