“That means that everybody needs to have some capacity to devote to change. This is time that people dedicate to rethinking how their piece of the whole works, and how it ought to work. Once the change is under way, more time is required to practice new ways and to master new skills. That’s the cost. The benefit is vitality and a firm grip on the future. Slack is the way you invest in change. Slack represents operational capacity sacrificed in the interests of long-term health.”