Fatigue failures of metal structures, for instance in working machines and energy production equipment, cause breaks in production and processes. Failures caused by the errors in design and analysis, and on the other hand, the redundant over-dimensioning of structures are both undesirable issues. LUT University originating realtime fatigue monitoring (ReFaMo) system is based on the life cycle assessment of devices and structures from the mechanical status viewpoint. The system measures loading history of structural components, and generates end-of-life estimation of structural components.