kijangnim,
If it uses the same wind, how can you explain the time difference between the ND and the MCDU?
You were saying the ND prediction uses the distance based on the bearing between the aircraft position and the waypoint, whereas on the MCDU is based on the active leg (which could be great circle, rhumb line, Arc ....). I have noticed the time difference even the waypoint is just 10/20NM away. How can the actual distance or great circle distance be so much different when the distance is so near?