I have worked in services companies (McKinsey and American Express) and product companies (RJR Nabisco and IBM). I will state unequivocally that services businesses are much more difficult to manage.

The implications of this kind of leap to a company’s economic model can be devastating. In IBM’s case it meant the collapse of gross profit margins and the attendant changes we had to engineer to lower our cost structure without compromising our effectiveness.

Yet the hardest part of these decisions was neither the technological nor economic transformations required. It was changing the culture—the mindset and instincts of hundreds of thousands of people who had grown up in an undeniably successful company, but one that had for decades been immune to normal competitive and economic forces.

This kind of wrenching cultural change doesn’t happen by executive fiat. As I found, I couldn’t flip a switch and alter behaviors. It was, by any measure, the hardest part of IBM’s transformation, and at times I thought it couldn’t be done.

Successful institutions almost always develop strong cultures that reinforce those elements that make the institution great. They reflect the environment from which they emerged. When that environment shifts,it is very hard for the culture to change. In fact, it becomes an enormous impediment to the institution’s ability to adapt.

This is doubly true when a company is the creation of a visionary leader. A company’s initial culture is usually determined by its founder’s mindset—that person’s values, beliefs, preferences, and also idiosyncrasies. It’s been said that every institution is nothing but the extended shadow of one person.

Great companies cannot be built on processes alone. But believe me, if your company has antiquated, disconnected, slow-moving processes—particularly those that drive success in your industry—you will end up a loser.