To make an optimum production plan by finding the restriction satisfying degree from the production start data and finding a production device from the production possibility, updating the state is a producing start data NN(neural network) and production NN and thereby changing the production stardata and the production device for each lot according to the assignment state if to other lots.

A dummy lot production means 2 generated the dummy lost of the same number of production devices for each lot against each lot based on the inputted order reception data and production capability data. A production start data NN 3 finds the production start date of each dummy lot, and a production start data NN output evaluation means 4 finde the restriction satisfying genre the formed satisfying degree. A producing device NN 5 decides the prosecution possibility of every production device based degree of each dummy lot based on the output of the NN 3 and output the limit sufficiency 3. A production device NN output evaluation means 6 fined the production service for each lot based on the output of the NN 5 and outputs the producing device information. Based on the output of the means 6, the NN 3 updates the production start data of each dummy lot.