1. A computer-readable, non-transitory medium storing therein an operation management support program causing a computer to execute a process, the process comprising: acquiring execution history information recording for each element group included in activity diagrams expressing work procedures for operation processes executed by a system under operation management, correlations between elements and access destinations of the elements; searching among a group of unselected elements that have yet to be selected from among all of the element groups, for a second element having an access destination coinciding with that of a first element selected from among all of the element groups, the searching performed by referring to the acquired execution history information; setting the first and the second elements as synonymous elements, if a second element is retrieved at the searching; extracting from among the element groups included in the activity diagrams that include the synonymous elements, a common element string of the elements common among the activity diagrams that include the synonymous elements; and outputting the extracted common element string.