Foreword: Why Scrum WorksSuppose I’m traveling from Chicago to Boston by airplane. Before and during the flight, the pilot gets instructions from air traffic control. We take off on command and follow the prescribed route. Once we are in the air, computers predict almost to the minute when we will land in Boston. If things change—say the air is bumpy—the pilot must get permission to move to a different altitude. As we approach the airport, the pilot is told what runway to land on and what gate to go to.If, however, I set out for Boston in a car, I can take whatever route I want, whenever I want. I don’t know exactly when I’ll get there, and I probably haven’t planned what route I’ll take or where I’ll stop for the night. En route, I follow traffic laws and conventions: I stop at red lights, merge into traffic according to the prevailing customs, and keep my speed consistent with the flow. In an automobile, I am an independent agent, making decisions in my own best interests framed by the rules of the game of driving.It’s amazing to me that thousands upon thousands of people travel by car every day, accomplishing their goals in a framework of simple traffic rules, with no central control or dispatching service. It also amazes me that when I want to ship a package, I can enter a pickup request on the shipper’s Web site and a driver will arrive at my door before the time that I specify. The driver isn’t dispatched to each house; he or she receives a continually updated list of addresses and deadlines. It’s the driver’s job to plot a route to get all the packages picked up on time.As complexity increases, central control and dispatching systems break down. Some might try valiantly to make the control system work by applying more rigor, and indeed that works for a while. But the people who prevail are those who figure out how to change to a system of independent agents operating under an appropriate set of rules. It might work to provid