Since the Beginning of 1990 s, Toyota has been pursuing a new direction in its human resource management and assembly work. After encountering a labor crisis-labor shortage and high turn over of young workers-during the economic boom provoked by the "financial bubble" toward the end of 1980 s, Toyota's management and Union discussed
ways of making the work more attractive. Based on this discussion, the production eugineering division developed a new kssembly line concept realized firstly at Toyota Kyushu plant (1992), applied also to Toyota's Motomachi No.2 plant (1994), Tahara No.1 plant (1995) and Motomachi
No.1 plant (1996). Among these plants, the construcion of the assembly line at Tahara No. 1 plant constitutes a unique case in the fact that it was not the production engineering division, but the foremen, supervisors and engineers belonging to the plant who conceived and constructed this new assembly line. Moreover, in order to realize what they considered as their ideal assembly line, they proposed to the product development center an important change of car structure and parts design from the very beginning of product development where the so called "concurrent engineering" has started. The first part of this paper explains, and thus why and how they conceived and constructed their own assembly line after presenting this assembly line concept and work orgnaization in this plant.