Sustainable Design and Analysis of CNC Machine Tools: Sustainable Design Index Based Approach and its Application Perspectives

In recent years, a major global challenge being faced in manufacturing industry, which requires low energy consumption, low pollution, low emission, less use of non-renewable resources, excellent market competitiveness and cost control capability, better protection of occupational health and safety, excellent technical performance, is to address the associated multifaceted context in environment, economy, society and technology. Many researchers and practitioners have thus been making great efforts in sustainable manufacturing in order to take on the challenges in a comprehensive and scientific manner. As the advanced manufacturing equipment, CNC machine tools particularly their design and applications need to adapt and cope with the increasing demands for sustainability capability and features. Incorporating sustainability at the design stage of CNC machine tools is an effective measure linking to the sustainable design and analysis of machines in particular. However, there is no universally accepted design guidelines and design methodologies for sustainable CNC machine tools yet. At present, many researchers and practitioners focus on one or two specific technologies, such as reducing energy consumption and reducing pollution emissions, for the sustainable performance of CNC machine tools. The study of the comprehensive quantitative analysis for the sustainable performance is still lacking. Therefore, in this paper a sustainable design index (SDI) oriented approach is presented for the machine design and analysis within the CAD/CAE environment. It is expected to be quantitative analysis oriented and applicable to the engineering manufacture in an industrial feasible manner. This analysis model quantitatively evaluates the design scheme of machine tools in four aspects covering environment, economy, society and technology, using the Life Cycle Assessment (LCA) and the Analytic Hierarchy Process (AHP) methods. This SDI analysis model consists of an indexing system, which can fully reflect the sustainable performance of design schemes, and a synthesis algorithm which can accurately calculate the sustainable design index value based on the following criterion levels: energy consumption, pollution emissions, costs, modular design, lightweight design, security, accuracy and processing capability. To enhance the application of SDI analysis model in CAD/CAE environment, we develop a new plugin program, which has been written in Visual Basic. This program can calculate the sustainable design index value for each design schemes by using original design values and weights. Using the approach and the associated tool developed, designers can determine a more sustainable machine design scheme, and further improve the sustainable performance of the machine by applying sustainable design index (SDI) based assessment indicators. A case study shows that the sustainable design performance of design scheme B is 38.10% better than design scheme A.