The material behaviour of forged components is subjected to an intensive influence of the manufacturing process. The local logarithmic strain as well as the cooling conditions may influence the cyclic stress-strain behaviour as well as the fatigue behaviour of the material. For a reliable lightweight design of components, those effects have to be considered already during early product development stages, because the definition of the component geometry will already imply process related limitations regarding the achievable local material propeties. A combination between a process simulation and a strain-based fatigue life estimation, including a customized testing strategy, allows a consideration of the manufacturing process influence as well as an implementation of statistical and mechanical size effects and improves the quality of the fatigue assessment and the reliability of numerically derived stress limits for component design compared to the state of the art.