GEOMETRY AND CAD / FIELD NOTE 11
Coordinating CAD Units and Project Datums
A correct surface can appear at the wrong scale or position after transfer. A common origin and unit convention give the two teams independent checks for alignment.
What to check on your project
Send the coordinate system, origin and one known dimension with the model. Include axis directions and specify whether the supplier may work in local coordinates. Record any transform needed to bring the part back into the project model.