In a conventional technique, it was impossible to execute processings up to an arbitrary processing among a series of registered processings depending on the situation from time to time. Thus, the only option in such a case was to newly register a new workflow depending on the need changing and depending on time. To solve this, a series of registered processings are displayed as a menu so that a user can select up to which processing in the series of processings should be executed. A not selected remaining processing can be executed by the user by allowing the user to later select a document once subjected to operations.