A document management method by using a computer includes: specifying, among a plurality of documents that belong to a most upstream development process, a document with which association indicating that the document has influence on a document that belongs to a downstream development process is not performed; specifying, among a plurality of documents that belong to a most downstream development process, a document with which association indicating that the document receives influence from a document that belongs to an upstream development process is not performed; and specifying, among a plurality of documents that belong to an intermediate development process, a document with which the association indicating that the document has influence on a document that belongs to the downstream development process or the association indicating that the document receives influence from a document that belongs to the upstream development process is not performed.