Professor of management practice in strategic and international management, London Business School
Big Idea: Welcome uncertainty in turbulent times.
Clients: Nokia, Mars, Baker & McKenzie
Sull didn't start off with ivory-tower aspirations. After four years at McKinsey and private equity firm Clayton Dubilier & Rice, he was drawn to academic life as he kept observing companies practicing "active inertia," or dealing with current problems "by accelerating activities that had worked in the past."
Sull, 45, now has new solutions for companies. One is to forget entirely about a grand vision, which locks them into vague promises or could commit them to a doomed strategy. The other is to embrace uncertainty, which he addresses in his upcoming book, "The Upside of Turbulence." The takeaway: Companies still need a map, but it needs to be focused on a few must-win battles and be fluid enough to be redrawn in the case of sudden shocks.
NEXT: Joel Podolny