In the 1960s and early 1970s, the emphasis in hospital information systems was on operational control—active monitoring of routine task performance, with emphasis on doing highly structured tasks better, faster, and cheaper. This operational control has been extensively achieved with systems such as patient accounting and medical records. The next era of application, which followed in the late 1970s and early 1980s, shifted attention toward functional effectiveness in the form of management control (Tan, 2001). In practice, this is often accomplished by data aggregation, analysis, interpretation, and presentation (Bali, 2005). Since the 1980s, a major trend has been the development of knowledge-based systems to support clinical care.