While large-scale MIS is being developed, what relation schema and power management system to set up greatly influences its initial development and later use. First, to solve the setup of relation schema concerning constant change in the attribute of an entity, a changing dimension based on the relational theory in tradition has been used for the setup of relation schema with a wide adaptability; second, to achieve effective power management where there are different standards for business classification on account of too many users and frequent alteration, a classifying power management system has been adopted for the realization of classified self-management model, making the whole system compact and flexible.