Supporting the Design of Reconfigurable Production Systems

University dissertation from Västerås : Mälardalen University

Abstract: To compete, manufacturing companies need production systems that quickly can respond to changes. To handle change drivers such as volume variations or new product variants, reconfigurability is advocated as a competitive means. This implies an ability to add, remove, and/or rearrange the structure of the production system to be ready for future changes. Still, it is not clear how the production system design process can capture and support the design of reconfigurable production systems. Therefore, the objective of this thesis is to increase the knowledge of how to support the design of reconfigurable production systems.Reconfigurability could be defined by a number of reconfigurability characteristics including convertibility, scalability, automatibility, mobility, modularity, integrability, and diagnosability. In eight case studies, reconfigurability characteristics in production system design were studied in order to investigate reconfigurability needs, knowledge, and practice in manufacturing companies. In three of the case studies reconfigurable production systems were studied to identify the links between change drivers and reconfigurability characteristics. In the remaining five case studies, reconfigurability in the production system design processes was addressed in terms of needs, prerequisites, and consideration.Based on the literature review and the case studies, support for reconfigurable production system design is suggested including two parts. The first part comprises support for analyzing the need for reconfigurability. Based on relevant change drivers the need for reconfigurability must be identified to enable selection of right type and degree of reconfigurability for each specific case of application. A comprehensive view of the reconfigurability characteristics is presented and links between change drivers and reconfigurability characteristics are described. The characteristics are divided into critical characteristics, that lead to a capacity or functionality change of the production system, and supporting characteristics, that reduce system reconfiguration time but do not necessarily lead to a modification of functionality or capacity of the production system. The second part provides support in how to consider reconfigurability in the production system design process. A holistic perspective is crucial to design reconfigurable production systems and therefore constituent parts of a production system are described. According to their character physical, logical, and human reconfiguration must be considered through the whole production system design process.