PURPOSE: To simplify work and to reduce time required for this work by automatically registering information such as a code or a unit price related to parts on an estimate list only by instructing the parts to be exchanged or repaired in the state of displaying the parts expansion plan of merchandise.

CONSTITUTION: When one group is selected by a pen 4, the parts expansion plan of the selected group is read from any one of bit map files 15a-15p and displayed on a screen. When a parts number attached to the parts is tapped in this state, the parts number and the parts name are displayed in a lowest column. When either exchange or repair in an instruction column is tapped, the parts name, parts code and normal price of tapped parts are read from correspondent parts code master files 17a-17m, this parts information is registered on an estimate file 18 provided inside a memory 6 together with the designated processing class 'exchange' or 'repair' and the contents of the estimate file 18 are displayed on the screen as the estimate lift.