The COHERENCE4D project aims at developing a new paradigm for modeling, visualizing, interacting, and maintaining the coherence of 4D digital twins interfaced with physical systems that evolve over time. The work will focus on the definition of a model with variable geometry and topology over time, on the development of update mechanisms, on the definition of a new methodology for the specification and integration of acquisition interfaces, on the development of a decision support system exploiting an Artificial Intelligence capable to analyze the real/virtual gaps in order to decide on the updates to be made, on the specification and the experimentation of new metaphors for the visualization and interaction with the 4D digital twins through AR/VR devices. The building blocks will be integrated within a demonstrator and the overall approach will be validated through several proofs of concept (POCs) on scenarios related to the maintenance of manufactured products, the reconfiguration of production systems, and the quality control on production lines.