PURPOSE: To keep the constant quantity of works carried out by an operator even if the quantity of part boxes delivered from an automatic warehouse varies, by recovering the box quantity which is obtained by adding the reduction correction quantity of the boxes based on the reduction quantity of the supplied part boxes for the standard quantity of the recovered boxes in the recovery of he vacant part boxes on a part shelf.

CONSTITUTION: When the quantity of the part boxes 2 which are transferred on a traction truck 7 is supposed to be 36 pieces, a management controller 10 demands the increase of the part boxes 2 by six pieces. The management controller 10 sets the increase correction quantity of boxes to three which is obtained by dividing six pieces by two. The management controller 10 determines the quantity of the part boxes 2 to be recovered to 12 pieces which is obtained by subtracting three boxes in the increase correction from 15 pieces to be recovered in standard. The management controller 10 controls the quantity 12 of the boxes to be recovered by a recovered box quantity instruction printer 20, and this quantity is printed out. An operator receives the printed-out paper sheet, and operates a traction vehicle 6 and pulls a traction truck 7. All the part boxes 2 transferred on the traction truck 7 are supplied on the part shelf 3 of a production line 1, and twelve vacant part boxes are recovered.