The book "The machine that changed the world" is about a study on the future of the automobile industry. Researchers found that lean production, like at Toyota, combines craft and mass production to be more efficient and flexible. This approach uses less inventory, has fewer defects, and offers a greater variety of products. It changes how people work by requiring more skills and teamwork. The book is divided into three sections: the origins of lean production, how it works in different areas, and how it is spreading worldwide. It suggests ways for companies to become leaner and more efficient.