A CPU of a data integration server detects first rare words whose number existing as words relating to configurations of tables of a factory data model is equal to or smaller than a predetermined number, detects second rare words whose number existing as words relating to configurations of tables in a common data model is equal to or smaller than a predetermined number, determines whether or not determination conditions for determining that a second column included in the common data model is a synonymous column candidate of a first column of the factory data model are satisfied, and, in the case where the determination conditions are satisfied, selects the second column as the synonymous column candidate of the first column. The determination conditions include a condition that one of the first rare words around the first column matches one of the second rare words around the second column.