1. A non-transitory, computer-readable recording medium having stored therein a program for causing a computer to execute a process, the process comprising: specifying a first relevance between machine parts by processing machine part documents which include design information of the machine parts, the first relevance being specified when there is one or more of a contact, assembly, welding, and kinematics relationship between two or more of the machine parts, and extracting a keyword of each of the machine part documents, each machine part document including design information of a machine part that has the first relevance; specifying a second relevance between electronic parts by processing electronic part documents which include design information of the electronic parts which control the machine parts, the second relevance being specified when there is an electrical connection between two or more of the electronic parts, and extracting a keyword of each of the electronic part documents, each electronic part document including design information of an electronic part that has the second relevance; specifying a third relevance between source codes by processing program documents which include the source codes for causing the electronic parts or the machine parts to perform a processing, the third relevance being specified when a function is included in a source code and the function is called in another source code, and extracting a keyword of each of the program documents, each program document including a source code that has the third relevance; associating documents having a common keyword among the extracted keywords of the program documents, the electronic part documents, and the machine part documents so that the program documents, the electronic part documents, and the machine part documents are associated with each other, respectively; and displaying a screen on which a visualized relationship among the program documents, the electronic part documents, and the machine part documents which are associated is set.