A controlling unit of a replacement part management server specifies a maintenance target equipment and acquires order conditions from a responsible personnel terminal. The controlling unit acquires maintenance information and part information both relating to the maintenance target equipment. The controlling unit calculates prediction residual regarding target parts of an initial value setting process, and compares the prediction residual with the shortest cycle. When the prediction residual is smaller than the shortest cycle, the controlling unit sets the number of replacements in the part order data storing unit. When an initial value setting process regarding all the parts is completed, an order input screen is output. When an order request is received from the responsible personnel terminal, an order management server acquires part order data and transmits a preparation instruction of a PM kit to the purchaser.