Editor's Note: The New Food Chain A head of lettuce from the farmers market isn't going to cut it anymore. Locally-sourced food is becoming a sustainable business.

We hear a lot about reinvention--in business, politics, science and technology. It's the mantra of the age: Reinvent or relent. Businesses that fail to constantly challenge and remake themselves run the very real risk of becoming irrelevant.

Sometimes reinvention involves remaking a brand or rethinking a product--something as simple as shoes, maybe. Sometimes it's re-creating an experience, like the simple act of buying shoes.

It's anyone's guess why some companies don't reinvent, opting instead to crumble toward obsolescence. Sometimes arrogance prevents it. Sometimes the risks of change are too daunting to present to shareholders or investors. Sometimes the psychology of change is inhibiting. Mostly, it's just fear.