With the advance of computer hardware performance and database system technology, it has been practicable to store and to search for a large quantity of data. So that Local modeling method, such as Just-In-Time modeling, has become very attractive in recent years. We have developed "Large scale database-based Online Modeling" as the practical method based on the Just-In-Time modeling concept on blast furnace operation, which has very complicated physical phenomena and strong non-linear specific characteristics. The validity of the developed modeling method has been confirmed by the study with blast furnace operation data, then the past similar operation data have been searched and the prospective operation data have been estimated very quickly and precisely.