Abstract: With use of a relationship analyzing section for analyzing the relationship between constituent elements of a requisition sheet model described, for example, in the form of use case, and a relationship output section for outputting the analysis result to, for example, a display unit, an operator can check the presence/absence of an omission, contradiction, and the like in the displayed relationship between constituent elements, thereby easily checking whether the requisition sheet is accurately described. In addition, with use of a use case executing section for sequentially executing use cases included in a requisition sheet and a log recording section for recording a log by recording the process of executing each use case, the process of executing each use case included in the requisition sheet is recorded as a log, thereby allowing a scenario representing the operation of a system to be easily created by only sequentially executing use cases.