A Computerized Physician order entry (CPOE) system was successfully implemented at the Ohio State University Medical Center (OSUMC) in February 2000. The electronic entry and use of order sets is designed to standardize patient care and improve efficiency and patient safety. To evaluate the effectiveness of the CPOE system and to maximize its benefits, one needs to easily access and analyze the data. Since the CPOE system is not equipped to support such on demand analysis, the data from the system is extracted daily into the OSUMC's Information Warehouse (IW). This allows the CPOE data to be linked with other clinical and financial patient information in the IW to provide detailed and comprehensive analysis. Our focus in this paper is the use of the IW as a tool to analyze order set usage patterns and the opportunities such analysis provides for improvements in education, resource utilization and patient care.