Factories (102 104) have host computers (107) for monitoring industrial equipment (106). Each host computer (107) is connected to a management host computer (108) on a vendor (101) side through the internet (105). The host computer (107) on the factory side detects occurrence of a trouble of the industrial equipment (106) and notifies the vendor side of status information representing a trouble state. In response to this, the host computer (108) on the vendor side notifies the factory side of response information representing a countermeasure against the trouble state.