A component mounting system includes a component mounting line in which a plurality of processing devices are connected to constitute the component mounting line and a management device (management computer) connected to the component mounting line by a network, and each of the plurality of processing devices can be remotely operated via the network by an input unit of the management device. In this component mounting system, it is determined whether or not an error occurring in the processing device is a remote response error (ST1), and notification in a first notification pattern is performed (ST2) in a case where a type of the error is the remote response error (Yes in ST1) and notification in a second notification pattern is performed (ST3) in a case where the type of the error is not the remote response error (No in ST1) based on a result of the error type determination.