This book comes from the author''s PhD thesis for the PhD in "Economia e Finanza nel Governo dell''Impresa" ("Business administration and finance for firm''s governance" at University of Rome La Sapienza, in Italy.The work was written in 2003 during the author''s research semester at the Faculty of Economics of University of Nagasaki in Japan. The book attempts to explain why and how the lean production is deeply rooted in the Japanese culture and the Japanese business environment. In order to understand the Japanese supply chain we first have to understand what Japanese do in their factories and how they do it. Considering production and business environment as a unique fields of study and research the book discusses and sheds the light on the links among them in the Japanese business contest. This is done analyzing the single elements of lean production and JIT while considering the uniqueness of Japanese business system, in order to demonstrate the relations between the business system and the organization of production and supply chain in Japan.