Real Time eXecutives, Inc., a software supplier to the Plant Information (PI) industry, has a mission to make available and improve the use of process and manufacturing information. We excel in collecting, storing, and providing historical process data. To meet that goal we have developed the OPC Historical Database System (OPCHDB). By interfacing to standard OPC DA Servers, OPCHDB collects a complete copy, or a subset, of  process data for historical storage. Then OPC HDA Clients, at desktop personal computers, can have a quick and secure retrieval of data for review and analysis. Process data is kept current through an automatic "minute-by-minute" updating procedure.