PURPOSE: To make it possible to detect an abnormality on a turnout at each process, by providing a display means to display the number of manufactured products on a display board based on an output signal from a sensor, and a display means to display an abnormality on the case when a tact width is not within a set tact width, based on a comparing result from a deciding means.

CONSTITUTION: A target value planned per one set or one kind of a device in a production line and a kind of a device are displayed on a display board 11 by means of a display means 14. Further, based on a production necessary quantity per one hour a production necessary quantity at a present point of time is computed by a computing means 15. A computing result therefrom is displayed on the display board 11 by a display means 17, and a product carried out in a main process is detected by means of a sensor 18, and the number of manufactured products is displayed on the display board 11 by a display means 20. It is decided by a deciding means 21 whether a tact width is within a set tact width, and when it is not within the set tact width, abnormal ity display is effected on the display board 11 by an abnormality display means 23.