There is an ongoing evolution of digital survey-based practices from linear to cyclic workflows. Past and current innovative projects, including EU initiatives (COST-COSCH, SCAN4RECO, ITN-CHANGE), are no longer one-shot isolated case study applications that build and explore a single-sourced digital model. Instead, Digital Heritage (DH) innovation is related to complex scenarios where the digital model is used to represent, renew, and discuss over time the added knowledge of multi-source virtual reconstruction. We cannot consider our production methods made of straightforward I/O operative chains; instead, we should see them as part of a system. Involving the principle of a systemic approach helps to embrace the multiplicity and complexity of DH practices and supports the definition of multimodal layers. The cover image shows a diagram of multimodal layers in the Cultural Heritage domain.