In 450mm wafers production environment for next generation Fab, one of the most significant features is the adoption of full automation to the whole manufacturing processes involved. The full automation system will prevent the workers from intervening the manufacturing processes as much as possible and increase the importance of each individual wafer noticeably, and thus require a more robust scheduling system for entire semiconductor manufacturing processes. The scheduling system for 450mm wafers production also should be capable of monitoring the status of each individual wafer and collecting useful Fab data in real time. In this study, we first analysis of cluster tool in 450mm wafers production environment, and then propose a real-time scheduling algorithm based on timetabling algorithm.