1. A computer-readable, non-transitory medium having stored thereon a workflow modeling program, the workflow modeling program causing a computer to perform a procedure comprising: consulting an update history information storage unit to generate flow information in which data set names of a plurality of data sets updated in a data update process are arranged in chronological order of updated time, oldest first, for every data update process, and counting a number of appearances of flow information of same in all of the generated flow information, the update history information storage unit storing process identification information uniquely identifying the data update process, a data set name of a data set updated in the data update process, and an updated time of the data set in association with each other, the data update process including update of the plurality of data sets; arranging workflows represented by the generated flow information in decreasing order of the number of appearances, sequentially selecting the workflows in decreasing order of the number of appearances until an accumulated number of appearances reaches a preset threshold, and classifying the selected workflows as typical workflows and unselected workflows as exceptional workflows; displaying one of a typical workflow diagram and an exceptional workflow diagram, the typical workflow diagram including nodes corresponding to the data set names and indicating the typical workflows, the exceptional workflow diagram including nodes corresponding to the data set names and indicating the typical workflows and at least one of the exceptional workflows; and switching, in response to user input, a diagram to be displayed from the one of the typical workflow diagram and the exceptional workflow diagram to another one of the typical workflow diagram and the exceptional workflow diagram.