Correcting globally units global set up

actually the unit set up is not working properly for me, because when you export your model the scale is wrong. the workaround is to set up the unit manually by 0.001 to get the export working correctly. but the bad thing is that you got to correct everything evry where like camera clip, size of object at creation grid ect ect ect. so is there a way to globally set blender so as to get everything with units properly set for export? and get all the software using the same information?
Hope i m clear
best regards