The DGN format has been used especially for data transfer between plant design programs. It was developed by MicroStation. It is similar to DWG in that it is only a graphical data format. It contains unique part IDs in the given model. It is possible to check for clashes between the Tekla Structures model and a DGN reference model.
This format has the following limitations:
GUID is not supported.
DGN reference model import does not support change management or UDAs.
3D DGN export supports parts only.