t This paper is intended to provide a method of setting up the Management Information System of a factory by introducing a large application software. By analysing the difference between the function and information required of the current user system and the software introduced, and according to the possibility of modificatin, a concrete method of the user work redesign and the software redesign is presented. It expands the work required of the method of life cycle when the management information system of a factory is set up by introducing a large application software.