Green production for a sustainable world has increased in importance as society has increased in its awareness of global warming, energy security, pollution, and the metals shortage. Lean production is a concept considered in successful manufacturing enterprises. Green and lean are often achieved together, such when both waste and energy consumption are reduced. On the other hand, the two are sometimes thought to be at odds, such as when the frequent transportation and small lot size often used in lean production consumes more energy usage than does conventional production. The integration of green and lean is familiar to those who study sustainability. The three bottom lines of sustainability are ecological, economic, and social sustainability. The ecological and economic dimensions have been discussed in the field of production systems. Proactive scenario simulation is required for the evaluation of sustainability as well as for the discussion of integrated criteria of sustainability.
This special issue covers both green and lean topics in the production field. It considers the challenges that need to be addressed so that researchers and practitioners may engage in scientific and practical discussions of these topics. Six contributions from academic institutes and six contributions from manufacturing companies have been accepted. This special issue is expected to encourage both academics and practitioners to discuss future collaboration. Most contributions deal with integrated green and lean issues. Some academic papers evaluate sustainability. Case studies as technical papers or development reports have been provided by industrial contributors. Methodologies range from survey to life cycle assessment to simulation to implementation. The applications range from machine development for green production to national technical policy for sustainable manufacturing.
All papers were refereed through careful peer reviews. We would like to express my sincere appreciation to the authors for their submissions and to the reviewers for their invaluable efforts, as together they made possible the publication of this special issue.
Lean Manufacturing (LM) has always been intended as a means to improve efficiency by reducing operations costs, but the recent focus on sustainability and its three pillars (economic, environmental, and social) raises new issues. In this paper, a new model that links LM with sustainability is proposed and then refined through a cross-sector multiple case study. The results highlight a need to align lean implementation processes with sustainability strategy to avoid negative impacts that LM could have on the components of sustainability.
There is increasing concern regarding sustainable supply chain management (SSCM). This paper defines SSCM in terms of environmental, economic, and social dimensions, also known as triple bottom line plus risk management. Prior to the SSCM serious game (SG) “Chain of Command (CoC)” there were no board-based SGs that incorporated the three dimensions of SSCM. Prior research has only managed to incorporate one or two dimensions of sustainability. “CoC” serves as a tool to bring about discussion, awareness, raise questions, and even identify a player’s preference towards the three dimensions of sustainability. The research results reveal that “CoC” does bring about awareness of SSCM. While encouraging players to carry out green activities and design a lean and efficient supply chain (SC), it also considers social implications and risk management.
This research focuses on the relation between time variation and the behaviors of a closed-loop supply chain with stochastic product returns. In recent years, activities that reduce environmental impact, such as recycling and reusing materials, have been increasing. Designing a closed-loop supply chain for recycling or reuse operations will support social responsibility and competitive advantage. However, in order to establish supply chains for sustainability, it is necessary to consider not only environmental benefits but also economic efficiency. Moreover, both the quantity of demand and returns are indefinite in an actual closed-loop supply chain. In this study, we assume that the arrival interval of return inward follows a logarithmic normal distribution. Further, we design basic models with a manufacturing and remanufacturing process to understand the behavior of a closed-loop supply chain with stochastic product returns in a finite horizon and investigate the influence of different choices in management on the cost and environmental factors.
Electric vehicles (EVs) are considered a promising technology to mitigate air pollution and resource depletion problems. The emissions from the manufacturing process can cause severe health problems like chronic asthma and even death. Automakers and policy makers need to investigate the lifecycle emissions of EVs in different regions and then governments should decide if it is safe to establish EV production facilities in their country or whether it is more appropriate to import finished products. The objective of this study is to evaluate the air pollutant emissions produced by EVs and gasoline vehicles (GVs) during their life cycles under two technology scenarios. Life cycle analysis (LCA) was applied to quantify greenhouse gas (GHG) and non-GHG emissions. We assessed air pollution from vehicles in Japan, China, and the United Kingdom (UK). Results indicate that EVs do not necessarily decrease pollutant emissions. EVs can improve air quality and reduce emissions in countries where electricity is derived from clean energy resources.
There is a strong need to address climate change issues by mobilizing a variety of technologies, including renewable energy technologies. In this paper, we focus on photovoltaic (PV) technology because solar cells or PV panels are already popular in many countries, mainly incentivized by a feed-in tariff (FIT) program and low production cost. However, it is difficult to accurately predict future PV installation capacity for a region because of a variety of uncertainties, such as national energy policies and consumers’ lifestyles. Taking such uncertainties into account, this paper takes a scenario design approach to analyze future PV deployment, thereby helping to examine policy implications and offering appropriate actions. A case study of Japan’s PV deployment scenarios up to 2030 is presented here. Four distinct future situations are assumed, with particular focus on technological advancement and national share of nuclear energy. The results show that solar power generation in 2030 could account for 3.4%–7.4% of the national electricity demand.
For achieving a sustainable society, clean energy vehicles (CEVs), such as electric and fuel cell vehicles, can play a significant role in reducing CO2 pollution in the transport sector. Each type of CEV has certain characteristics: vehicle running range, Life Cycle CO2(LCCO2), cost, fuel efficiency, etc. Therefore, in order to accomplish CO2 reduction targets in the UK, this paper calculates optimized CEV portfolios by considering each CEV’s characteristics. The objective is to minimize a CEV system that includes running, vehicle manufacturing, and infrastructure costs. Constraints are defined by the vehicle sales number, vehicle price, energy price, etc. A CEV optimized portfolio is calculated for each year to provide ideas for determining future CEV policy for government and industries. Few conventional studies show optimized CEV portfolios by considering mixed rates of renewable energy sources (RES). However, they did employ one case of RES introduction rate, but this study employs many RES introduction scenarios. Results suggest that introducing a high RES date contributes to reducing EV’s LCCO2 dramatically and reaching the UK target without great reduction of GVs and DVs. In the scenario of high RES introduction rate, differences are widening among EVs, GVs, and DVs in their amounts of CO2 pollution.
Global warming is one of the most important environmental issues that the world faces today. Reducing energy consumption is critical in industrial environments. Machine tools have some of the highest energy consumption rates of all the equipment in factories. This makes it important to reduce machine tool energy consumption to protect the global environment. Some effective ways of reducing the energy consumption of machine tools are by reducing the required energy, shutting down the power to standby mode, and shortening cycle times. This paper introduces several approaches to the reduction of energy consumption.
Environmental measures are urgently required to realize a society with a low environmental load. In response, various undertakings are being carried out in the field of machine tools, which is most critical in terms of requirement of energy-saving measures. The energy consumed when a machine tool is used to machine can be broadly divided into three categories: the “standby energy” to maintain the electrical devices operational when the machine is not operational; the “steady-state energy,” which is the fixed amount of energy required when the machine is in operation; and the “dynamic energy,” which varies with the machining conditions and other factors. Measures are necessary for each of these energy categories to reduce energy consumption. This paper describes an example of an energy-saving study undertaken for a machine tool used for machining gears; a new processing method called skiving was developed to consolidate work processes.
In this paper we explain how Ricoh have developed and applied a Green and Lean framework at their manufacturing site in Telford (UK). The paper shows how the site has adopted and adapted the Ricoh corporate philosophies  of Kaizen and Sustainability, learning from doing and then learning how to share these aspects with stakeholders. These activities demonstrate multiple business benefits of addressing process inefficiencies and waste resource usage, which in turn improve business performance and ultimately survivability (business continuity).
To succeed in a global business environment, the competitiveness of both products and manufacturing is inevitable. Therefore, the leanness of entire supply chains is considered necessary. A 1/N machine that was consistently synchronized with the assembly process was developed and introduced in a factory to alleviate bottlenecks in machining processes.
This paper reports on the development of a low-cost machine vision inspection system to promote the wide employment of the system and foster further quality improvements in automobile manufacturing. The machine vision system consists of a camera that takes images of an inspection target, lighting to ensure appropriate illuminance, and a controller that analyzes the images and gives inspection results. By optimizing the performance and using free software, we succeeded in the development of an ultralow-cost machine vision system for one tenth of the cost of commercially available factory automation machine vision systems. The development and results are introduced in this paper. The applicability of the ultralow-cost machine vision system platform to applications other than inspection is also discussed.
Today, many of the resin parts of automobiles are molded using the injection molding technique with high productivity. In the case of a large part, for which a mold clamping force of more than 2,000 t is needed, it is common that a piece of the part is manufactured with one metal mold and the parts with bilateral symmetry are manufactured simultaneously with a separate one. This development focuses on the advantage that productivity could be enhanced and the cost for a metal mold could be reduced by utilizing the space in the mold cavity for a large part and making another metal mold for a small part. To mold a large and small part with a large volume ratio simultaneously by using one metal mold, the fluid distribution of molten resin suitable for the volumes of both parts is necessary. Without realizing the associated fluid distribution molding defects, such as short, sink, or the like, would occur. In the case of the large part, such as a bumper, molten resin flows from the injection unit through a hot runner unit within the metal mold and subsequently, each gate into each product. To distribute the appropriate amount of resin to the large and small parts through a hot runner, the molding technique involves distribution of the fluid to each gate with an appropriate balance by controlling flow through the valve of a hot runner; this paper discusses the aforementioned technique.
Because the energy and the power of the molding machine to melt and inject the resin can be reduced by molding two deferent parts with one die, this family mold can contribute to Green production.
This paper presents analysis results of molten metal vibration for the pouring ladle of an automatic pouring system and proposes vibration suppression control during backward tilting of the ladle in the pouring cut-off process. The pouring ladle has a weir to avoid contamination of the molten metal. The weir separates the interior of the ladle into a body side and a nozzle side. First, weir effects on flow behavior are analyzed by comparing ladles with and without weirs using computational fluid dynamics simulations. In this analysis, a trapezoidal shaped input is designed as a backward tilting velocity. As a result, molten metal in the ladle with weir shows not only sloshing but also moving-volume vibration at the weir opening area. Secondly, the center points of the tilting motion are each verified by residual vibrations using FFT analysis. The frequencies of vibrating elements are nearly identical; however, analysis results show that the sloshing magnitude varies with changing center point of the tilting motion. In addition, effects of weir position and opening area on peak frequencies are analyzed. Each condition affects a frequency of moving-volume vibration. In addition, weir position changes sloshing frequencies at both body side and nozzle side of the pouring ladle. Finally, the suppression control input for each vibration is designed using the Input Shaping control approach. Design parameters for the control input were identified from residual vibrations, and assumed to be a second-order lag system. The effectiveness of the proposed suppression control input is verified by comparison with the non-controlled case.
We propose a line-based region growing method for extracting planar regions with precise boundaries from a point cloud with an anisotropic distribution. Planar structure extraction from point clouds is an important process in many applications, such as maintenance of infrastructure components including roads and curbstones, because most artificial structures consist of planar surfaces. A mobile mapping system (MMS) is able to obtain a large number of points while traveling at a standard speed. However, if a high-end laser scanning system is equipped, the point cloud has an anisotropic distribution. In traditional point-based methods, this causes problems when calculating geometric information using neighboring points. In the proposed method, the precise boundary of a planar structure is maintained by appropriately creating line segments from an input point cloud. Furthermore, a normal vector at a line segment is precisely estimated for the region growing process. An experiment using the point cloud from an MMS simulation indicates that the proposed method extracts planar regions accurately. Additionally, we apply the proposed method to several real point clouds and evaluate its effectiveness via visual inspection.