The logistics of Just-in-Time between parts suppliers and car assemblers in Japan

This study is an attempt to elucidate the spatial structure of “Just-in-Time” (JIT)-based logistics for the distribution of automotive parts in Japan. A diverse range of opinions on spatial structure have been presented in economic geography in the West: namely the ways in which implementing JIT causes the locations of parts suppliers to become concentrated or dispersed; and the things which can be considered as contributing factors in such concentrations or dispersals. In response to this, the authors of this paper decided to carefully clarify the reality of such logistics in Japan by considering case examples of certain automotive parts suppliers which have implemented JIT from early on despite being located far from their respective car assembly plants. The authors will also shed light on the fact that, in order to accommodate distribution from remote locations, cross-docks operated by third-party logistics providers (3PL) are located near car assembly plants, and will seek to further clarify the functions of these cross-docks. This analysis has also enabled new insights to be gained: concentrations of suppliers such as in Toyota City are exceptions to the norm, and that instead suppliers tend to be dispersed over a wide area in Japan; even in JIT-based logistics, economies of scale are being pursued and inventories are being stored; and in deliveries to car assembly plants 3PL cross-docks are performing an important function in making small-lot, high-frequency deliveries.