Herbert Simon is unique in our discipline in terms of the far-reaching impact which his work has had on management and the understanding of managerial decision making, especially when his further work with James March is considered. Mintzberg himself, who considerably advanced our ideas on management practice, noted that he always considered Simon to be the most influential and important contemporary author in terms of organizational theory (1990, p. 94). Jared Cohon, president of Carnegie Mellon University, where Simon was a fixture for 52 years said “few if any scientists and scholars around the world have had as great an influence as had Simon across so many fields, economics, computer science, psychology, and artificial intelligence amongst them.” Indeed, Herbert Simon’s contribution to management and DSS is such that the science and practice of management and decision making has been durably changed under his influence. This article considers the new ideas brought by Simon in management theory and looks at his contribution to our understanding of managerial decision making and DSSs.