1. An information processing apparatus comprising: a user authentication unit that identifies a current user; a task acquiring unit that acquires task information of a relevant task associated with a document file to be processed by the current user; an operation log storage unit that stores operation log information indicating executed operations and, for each specific operation of the executed operations, a particular task associated with the specific operation; and a file information storage unit that stores file information of the document file to be processed in association with the task information of the relevant task, wherein the task is a resource related to work or a business activity of the user and has a task ID associated with the task, and the document file has a document ID associated with the document file, and in the stored file information of the document file, the document ID of the document file is associated with a document title of the document file, the user ID of a particular user who stored the document file, the task ID of the relevant task, and the time/date at which the document file was stored, and wherein the information processing apparatus further comprises: an operation command unit for designating the document file to be processed; and a candidate operation indicating unit that determines, when the document file to be processed has been designated, one or more candidate operations, by referring to the file information stored in the file information storage unit to determine one or more task IDs associated with the document ID of the designated document file, and referring to the operation log information stored in the operation log storage unit to determine one or more logged operations associated with the one or more task IDs.