Fatigue analysis is established as important complement, based on a stress calculation, in industrial applications. The additional findings are used to design components and assemblies in lightweight construction. As an independent simulation, the fatigue life analysis leads to additional requirements for the simulation process. This includes the exchange of large amounts of data between software/compute servers with different interface formats and changing assignment of individual data as well as different model descriptions or namespaces. The implementation and error-free use of this process is the responsibility of the user and is not part of the individual software. In addition to data handling, the different release periods of the software involved must also be considered. As a solution, the complete integration of the fatigue life analysis into a general FEM solver is presented. Both parts of the analysis, the classic stress analysis, and the fatigue analysis, are based on a common data model and use the same resources. This guarantees data efficiency (large data remains internal, double data handling is avoided) and the import/export or archiving of intermediate results is no longer necessary. Further advantages result from the simple use of additional results, which previously could not be used due to a lack of a suitable interface. For example, of stress gradients, which were previously additionally calculated by the fatigue software based on their own model data and are now available in better quality directly within the FEM software based on the original FEM model. This can be used to increase the quality of the results. Due to the elimination of data exchange and the HPC orientation of the FEM software, the integrated service life analysis benefits significantly in terms of performance. New analysis classes are made possible by reduced amounts of data. The stress results from large models combined with many analysis steps often exceeded the memory capacities and thereby completely prevent fatigue analysis or allow only low accuracy. Due to the integration, the complete stress results for all calculation steps no longer have to be saved, but are used directly (“on-the-fly”) by the fatigue analysis in each calculation step and then deleted again immediately. This significant process improvement means that new classes of model sizes and significantly more result steps can be taken into account. The results are then much more accurate. All advantages are illustrated using a practical example from industry. The focus is on process simplification and the reduction of computing time. A subsequent outlook shows which applications can also be opened up by this innovative approach.