An object of the invention is to provide a remote server that can determine occurrence of an abnormal condition in a power transmission system without using a threshold value in advance. There is provided a remote server (5) that receives operating and non-operating information of a working unit, information on a working date, information on a traveling speed, and information on a load factor of an engine, respectively from a combine harvester (3). The remote server (5) calculates for each predetermined period an average (Lm) of the engine load factor (L) while the traveling speed is at or above a predetermined traveling speed (Va) with all working units in non-operation. If the average (Lm) during a predetermined period is in a status of a predetermined difference from the average (LM) up to the predetermined period, the remote server (5) determines that a moving power transmission mechanism of a traveling system of the combine harvester (3) is in an abnormal condition.
