The link between real structure and digital twin is existential for the topic of the planned Collaborative Research Center. For this purpose, precise and robust monitoring concepts and suitable model fitting procedures are required. These concepts and procedures should be realizable with the help of conventional and already proven measurement technology and sensor technology. Therefore, own metrological new developments within the framework of the Collaborative Research Center are not planned. The planned focus of project area C is the investigation of the linking of the real with the digital twin, although a real twin will only exist in future industrial applications. Here, the failure and temporal change of sensor signals over the lifetime with increasing knowledge of structural behavior, damage detection and localization, and intelligent and adaptive control of offshore megastructures will be considered.