A Lean Manufacturing Roadmap for an Automotive Body Assembly Line within Axiomatic Design Framework

In this paper we are to present a practical application of Axiomatic Design (AD) methodology, as a roadmap to lean production, in redesigning a car body assembly line. Axiomatic Design theory provides a framework to simplify the whole problem. According to the AD principles, a hierarchical structure has been developed. The developed structure originated in lean manufacturing principles and existing conditions of an assembly line, revealed that elimination of all kinds of waste is a prerequisite for other functional requirements. Several main sources of waste were recognized in the assembly line and some practical solutions are suggested to alleviate these problems. In the initial survey, it became obvious that high work-in-progress is the major problem of this assembly line, which is the symptom of an unbalanced flow. Two cells have more problems than others and require to be modified first: the door cell and the underbody cell. Based on the hierarchy, these cells are redesigned. In addition to interior space of the cells, two automatic material handling systems -overhead chain conveyor- are employed respectively to facilitate handling operation of these cells. Main Line is another part of the assembly line, have to being modified by adding spot welding robots. The proposed plan is justified both technically and economically to the managers of the assembly line.