For more than a quarter of a century, Madan G. Singh taught and accomplished seminal research on approaches to better control, manage, and understand complexity in systems. This interdisciplinary work has covered the intersections of the areas of control engineering, systems engineering, applied mathematics, management science, and computer science. His work has been remarkable at both a theoretical level, as well as at a practical level. Indeed, over the years, his practical work has led to new insights which have driven the theoretical developments. He has examined complexity in human-made systems, in managerial decision making, in marketing, and in production planning and scheduling. He has taken full advantage of contemporary developments in computing technology and in organizational science. He was, in a great many respects, a truly excellent exemplar of the modern academic, with highly tuned entrepreneurial skills integrated with major research skills. His career reflects well the contemporary changing character of academia that is now simultaneously home to ivory tower research, pragmatic market-driven research and associated product and service development. The purpose of this commemorative paper is to describe the evolution of his academic, research, scholarship, professional service, and enterprise efforts over the last two and a half decades.