Mark Mortensen, an associate professor of organizational behavior at INSEAD, discusses the research on "multiteaming"—when employees work not only across multiple projects, but multiple teams. It has significant benefits at the individual, team, and organizational levels. Among them: multiteaming saves money. The cost—stretched employees—is hard to see. And that is where the tension, and the risk, lies. Mortensen is the co-author, with Heidi K. Gardner, of “The Overcommitted Organization” in the September–October 2017 issue of Harvard Business Review.