In an electronic component mounting system, when a change in a recipe (setting data) for a control computer are input in any one of a plurality of circuit board working machines, such as component mounting machines, the control computer reports changed content to a host computer. The host computer, which receives the report, updates the data, which is stored in the DB server, based on the changed content of the recipe. The control computer, which receives input of the change in the recipe, executes a process in which only the partial data, which is updated by the host computer, is acquired among the data items, which are stored in the DB server.
