With the high speed innovation of information technology, many production scheduling systems (to support scheduling work) have been developed. However, a significant customization according to individual production environment is required, and then a large investment for development and maintenance is indispensable. Therefore now the direction to construct scheduling systems should be changed. The final objective of this research aims at developing a system which is built by itself extracting the scheduling technique automatically through the daily production scheduling work. By using the information extracted by the system, production scheduling operators can be supported to accelerate the production scheduling work easily and accurately without any restriction of scheduling works. In order to realize such a production scheduling system, the mechanism to extract scheduling information is needed. In this paper, using Gantt Chart Interface System that is developed to emulate the production scheduling work on papers through the analysis of operator's works, the method extracting and generalizing the relation information between operations from user manipulation is proposed. And the operator assistant function which uses the extracted information is proposed. Then by conducting experiment that uses the assistant function, the availability of the method of extracting and generalizing is shown.