How to make process data more valuable? This is a question every PI System user has often asked. This presentation will demonstrate how to use statistical process control, principal component analysis and computerized operator experience to perform a process monitoring system in a polyethylene plant. Since the plant frequently changes operating conditions according to market demands, this monitoring application can automatically load different control limits according to different product specification and checks the online process status. Furthermore, this monitoring application can calculate some key performance indexes that management should be informed about in every day operation. These performance indexes include productivity indexes, operator performance indexes and equipment performance indexes. These indexes are calculated every minute and summarized in the daily report, which is sent to the plant managers via email every morning.