If you ask any high school teacher what the biggest killer of class productivity is in a class of students after lunch they will tell you, in more or less the same words, it is inertia – the tired drag of disinterested students who will not act unless acted upon by an external force, often in the form of a frustrated teacher. The same goes for large and mature organizations. In business, just as it is in nature, size is almost always inversely related to agility, and inertia is the biggest killer of progress and productivity.