a non - transitory computer - readable recording medium has stored therein a mapping program that causes a computer to execute a process . the process includes : first calculating a matching rate between top - level parent items in a hierarchical relationship between a first plurality of items of a first data and a second plurality of items of a second data based on an item information relating to the first plurality of items and the second plurality of items , the first data including one or a plurality of items before a change , the second data including one or a plurality of items after the change ; and associating the parent items of the first data and the second data with each other based on the calculated matching rate .