The present invention presents a list of applicable services dynamically updated and enables users to specify selective combinations of the services. A client includes an input unit, a display unit, a user authentication unit, a service display and selection unit, a document set display and display unit, and the like. The service display and selection unit creates a list of currently active, applicable services and performs processing for user's service selection. The document set display and selection unit creates a list of documents included in a document set specified by a user and performs processing for user's document selection. In the servers, a service management unit, a selected service execution unit, service providing units, a document information management unit, a document storage unit, and a user information management unit operate respectively.