PURPOSE: To carry out efficient input planning operation by actualizing an efficient flow of articles through plural factories.

CONSTITUTION: Whether a necessary number 8 of materials required to manufacture an input object are held, whether or not the daily factory input limit 3 of the front-end factory for the manufacture of the input object, i.e., the daily facility capacity of the neck process having the least throughput among plural passing processes in each factory is exceeded, and the facility possible input limit 7 by next factory input dates of the input object, i.e., the actual possible facility input limit obtained by excluding the load of the input object in process that is predicted to be present at a next factory on the day of the input object to the next factory and already inputted to the process and the load of the input object that is already reserved in the input schedule, but not inputted to the process from the daily factory input limit at the next factory, is exceeded are checked to plan the input object which satisfies the three items.