Substantial improvement in fatigue life prediction has been effected by the introduction of cyclic stress-strain concepts. A procedure that incorporates these in a simulation of local stress and strain from nominal load using Neuber notch analysis is described in relation to its application to the fatigue analysis of in-service histories. In the present simulation the non-linear stress-strain and Neuber equations are solved numerically rather than by piecewise approximations. For the long load histories occuring in practice this improves numerical stability.