There is provided a management server technology that allows a user to continuously use a business function of a business server without logging in again to the business server, even if the authority of the user to the business server is changed. The business server receives an access from a user terminal, and requests a management server to perform user authentication. In response to the authentication request, the management server determines a future scheduled authority of the user, generates not only authority information at the time of the user authentication, but also a determination result including the future scheduled authority information, and transmits them to the business server. The business server provides the user terminal with a new business function based on the scheduled user authority information, upon expiration of a validity period of the user authority to the current business function.