Patent ID: 8103634

Claim:
A document management system, comprising: a management device that manages operation limiting information for limiting an operation of a document, and a document operation device that operates the document, wherein: the document operation device is provided with: an invalidation request portion that requests invalidation of the document, and the management device is provided with: an operation historical management portion that manages an operation history of a document for managing the operation limiting information, a policy information setting portion that sets policy information of the document based on a policy ID, the policy information including usage permissions, a related document retrieval portion that retrieves a related document related to the document according to the operation history managed by the operation historical management portion in response to the document invalidation request by the invalidation request portion, the policy ID of the document shared by the related document such that policy information of the related document follows the policy information of the document, and an invalidation portion that: sets invalidation information in operation limiting information on a document related to the invalidation request and a related document retrieved by the related document retrieval portion; and invalidates the document related to the invalidation request and the related document.