The concept of Industry 4.0 has been proposed by many countries for a full decade, and its theory has made a deeper evolution in the concept of lean manufacturing. In the first part, this paper provides a review concerning the development of Industry 4.0 processes in the U.S., China, Japan, and Germany on a technical level, and from each country 3 of the most famous cases are analyzed deeply. The second part of this paper explains the relationship between lean manufacturing and Industry 4.0 from the aspect of industrial cases and builds a concept of Industry 4.0 stages, which can evaluate the stage of the industry cases. A national- level report of the state-of-the-art concerning Industry 4.0 based on this concept is offered.