A shipyard or engineering model is built for designing and building the asset, so it carries full geometry, structural detail and fabrication information that operations rarely needs. An operational digital twin is built for running the asset, so it focuses on equipment, connections, locations and the live work happening on them.
Trying to use the engineering model for operations usually means a heavy model that is hard to keep current and hard for field teams to use. An operational twin should be lighter, tied to the drawings operations actually maintains and connected to permits, procedures and inspections, which is what makes it useful day to day.