A system complexity approach for the integration of product development and production system design

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999.Includes bibliographical references (p. 123-129).Complexity is generally believed to be one of the main causes of present difficulties in plant design and control. The complexity of a manufacturing system cannot be viewed without considering the products produced in the system. Lack of understanding in this relationship may lead to difficulties in product portfolio design and manufacturing system design. In this thesis, it is shown that by designing a manufacturing system properly, we can manage increased product variety while simultaneously eliminating system complexity. In addition, this thesis explains how 'lean' concepts eliminate system complexity. To see and compare complexity of manufacturing systems, complexity metrics are developed based on a complexity model provided by system theory. These metrics focus on sources of complexity to facilitate system improvements in terns of system complexity. With these metrics, a case study was carried out to apply these complexity metrics to a real industry case. In this case study, a lean manufacturing system that substitutes the existing mass-type manufacturing system is proposed and the impacts of this conversion on manufacturing system complexity are studied. According to this case study, the complexity of the proposed lean production system is much less than the complexity of the existing system in terns of proposed complexity metrics. Once the complexity of a manufacturing system is well understood, the manufacturing system can be designed to decrease complexity. In addition, product families can be designed for manufacturing systems and detailed product designs for manufacturing systems are possible.by Yong-Suk Kim.S.M