A decomposition-based approach for manufacturing system design

Abstract

The design of manufacturing systems is a complex task that requires many people to cooperate and communicate at various organizational levels. Companies often change the design of their manufacturing systems by using "off-the-shelf' solutions, such as Uformed manufacturing cells, without relating those solutions to overall system objectives. These ad hoc changes seldom have a formal process to guide them. This thesis contributes to the development of a manufacturing system design framework that satisfies five objectives: (1) it clearly separates objectives from means of achievement, (2) it relates low-level activities and decisions to high-level goals and requirements, (3) it states interrelationships among different elements of a system design, (4) it provides a common platform to effectively communicate this information across the organization, (5) it guides the designers through all stages of the system design. The framework is based on a recently developed Manufacturing System Design Decomposition (MSDD). This thesis reports on a multiple case-study research program that validates and modifies the MSDD. This research program led to the creation of a questionnaire that guides the systematic investigation and critical analysis of manufacturing systems. The reliability of this questionnaire has been tested successfully with Cronbach's Alpha factor. The thesis describes four groups of case studies that show how the MSDD provides a powerful tool to analyze the strengths and weaknesses of existing manufacturing systems. In addition, the thesis uses the MSDD to derive new manufacturing system designs. It shows that the MSDD is equally applicable across industry, manufacturing processes, production volume, and company size. The research in this thesis proves theoretical and literal replication of the premises stated in the MSDD. A database is developed to provide a graphical interface for the use of the MSDD, for documenting system design projects, and for analyzing the questionnaire. Modifications to the MSDD are recommended, based on the case studies. The thesis provides a basis for future research to integrate existing manufacturing system design methodologies with the MSDD.