Management of two competitive closed-loop supply chains

The two competitive closed-loop supply chains under our study include three members: two manufacturers and one retailer. In this paper, we focus on the management of the wholesale prices, the retail prices and the collecting prices for the two competitive closed-loop supply chains. On the assumption that the return rate of the used-products is an increasing function of the collecting price, we obtain the optimal wholesale prices, the optimal retail prices and the optimal collecting prices based on the following models: Model MMC (two manufacturers for collecting), Model MRC (manufacturer one and retailer for collecting) and Model RRC (retailer for collecting). Furthermore, by comparing the optimal results, we find that the retailer for collecting is the best channel for the two competitive closed-loop supply chains if the two manufacturers would like to transfer all of their cost savings from remanufacturing to the retailer. At the end, we illustrate a numerical example to analyse the impacts of the market share ratio and the substitute ratio of the two products on the optimal results.     

Closed-loop supply chain system with energy,transportation and waste disposal costs

Energy usage and consumption play important and strategic roles in modern manufacturing, inventory and logistics systems. The literature on inventory models for closed-loop supply chains reveals that, for no clear reasons, energy costs were ignored along with transportation and disposal costs. This paper introduces a closed-loop supply chain model that considers the economic value and energy content of products. It also offers a novel framework for studying lot-sizing policies of production processes in that context. Thus, a mathematical model for a closed-loop supply chain system with energy, transportation and disposal costs is developed. Numerical examples are provided with their results discussed. The developed model was also compared to that of Richter (1996) to stress the importance of accounting for the three noted costs. The numerical results emphasise that accounting for energy, transportation and disposal costs in supply chain modelling increases the sustainability of a production-inventory system due to the strong interdependence of the three costs on one hand, and their relationship to the environment on the other hand.     

A carbon footprint analysis in the textile supply chain

This research work focuses on the application of life-cycle assessment methodology to determine the carbon footprint of different players involved in a supply chain of the textile sector. A case study of a product by a textile leader company was carried out. This study demonstrates that, in the textile chain, the main contribution to the greenhouse effect is provided by the electrical and thermal energy used and by the transportation (since different production phases are delocalised in a wide range that goes from South Africa, Italy, Romania and all around the world, from the distribution centre to the stores). The Monte Carlo analysis has been used in order to obtain, for each calculated impact, not only the average value but also the distribution curve of the results characterised by uncertainty parameters. Moreover, a sensitivity analysis was carried out to evaluate the impact of management choices such as:

??a change in the transportation modality, from aeroplane to boat;

??a combination of road and rail transportation; and

??a selection among suppliers that allows the firm to cut environmental impacts.     

The study of production and inventory policy of manufacturing/remanufacturing environment in a closed-loop supply chain

The life cycle of electronic and electrical equipment has been ruthlessly shortened due to the rapid promotion of new products. Such a phenomenon has thereby resulted in serious environmental pollution and damages to the natural ecology. In order to reduce electronic wastes and increase recycling products, a manufacturing/remanufacturing simulation model was constructed through a series of inventory management policies. The model included the use of the traditional supply chain structures for the forward movement of goods to consumers, as well as a number of specialised operations required to perform reverse supply chain activities. Such a model took into account all the supply chain members such as the suppliers, manufacturers, logistics centres and customers at the same time. Finally, a case study on the application of the model was conducted.     

The impact of government subsidy and tax policy on the competitive decision-making of remanufacturing supply chains

In this paper, we consider a two-period competition model of a remanufacturing supply chain consisting of three members: a new product manufacturer, a recycler and a remanufacturer. The manufacturer supplies new products in the first period and the remanufacturer participates in the competition in the second period. We consider three scenarios in the second period: (1) there is no government subsidy in the competition; (2) there is only government subsidy in the competition; (3) there are both government subsidy and tax in the competition. First, we give the optimal decision-making of the manufacturer, the remanufacturer and the government in the three scenarios; second, we analyse changes in the decision-making of the manufacturer and remanufacturer in the three scenarios and compare their results. We analyse the effects of government subsidy and tax and their asymmetric use on manufacturers’ and remanufacturers’ decision-making variables and competitive performance. We also take consumer awareness of environmental protection into account and examine its impact on subjects’ decisions. Lastly, we operate a numerical example to show the results.     

Critical success factors of sustainable manufacturing practices in Malaysian automotive industry

The purpose of this study is to examine the critical success factors of sustainable manufacturing practices (SMPs) in Malaysian automotive industry. The questionnaires were designed and distributed to the 50 respondents. The pilot study sample consists of 26 respondents from 50 questionnaires, with an average response rate of 52%. The results of reliability analysis show that social responsibility is critical factor influencing the direct SMPs implementation success. By implementing SMPs in Malaysian automotive industry, it can assist company to improve the quality of management. Thus, this study recommends that the future research explore the influence of SMPs on sustainable performance in Malaysian automotive industry.     

再生资源供应链的结构、行为和绩效分析

再生资源是一种特殊的资源类型,兼具资源资产产权和环境产权,两者相互作用引导其开发利用自组织形成了正规与非正规回收利用者相互交织的完整逆向供应链系统。协调其中各主体间的利益关系、减少逆向供应链的环境污染和整体运行损耗是再生资源开发利用水平提升的关键手段。为此,本文以北京市废旧电视为例,利用实地调研的方法,系统分析了再生资源供应链的结构、行为和绩效(SCP)。结果表明:(1)消费者选择一级回收者时具有价值性、便捷性和规范性三种偏好。销售商回收模式可较好地满足消费者的需求,成为其首选方案,然而,"以旧换新"限制了无需购买新电视的人群。游商以45%的份额占据了剩余一级回收市场的主导地位。(2)一级与二级回收者间形成了稳定的合作关系,二手市场扩大了一级回收者的利润,中间商则为一级回收者提供了稳定的需求保障。(3)受到非正规拆解作坊的挤占,正规拆解企业产能严重过剩。一方面,降低了拆解企业对收购产品的质量要求,致使中间商偷换有价组件和跨境转移电子废弃物等问题日益严重。另一方面,正规拆解企业会提高收购价格,致使政府补贴的基金大部分转移至回收环节,巩固了现有的正规与非正规回收者共存的供应链结构。(4)个体中间商及非正规拆解利用作坊是再生资源供应链低效率的关键。本文调整了现有的家电基金制度,建议在电视销售环节向消费者征收40元/台的基金,并将其中的10元/台用于扶持政府可管控的正规主体中间商,代替个体中间商的功能,其余金额可用于弥补现有基金的亏空。该种模式可充分利用现有的一级回收者及二手市场,并可有效提升再生资源供应链的整体绩效水平。     

Sustainable product design using CAD: a case study in an Indian rotary switches manufacturing organisation

Sustainability is gaining importance in contemporary manufacturing organisations. Modern design engineers need approaches for creating environmentally friendly products. In this context, this paper reports a case study carried out in an Indian rotary switches manufacturing organisation. A component of the rotary switch has been modelled using computer-aided design. Then, the sustainability analysis has been carried out for determining the environmental impact. The environmental impact has been measured in terms of carbon footprint, energy consumption and air/water impacts. The handle design has been modified to minimise the environmental impact. The results of this case study indicate that appropriate modifications in design could lead to the development of sustainable design with minimal environmental impact.     

Issues in reverse supply chain,part III: classification and simple analysis

Due to growing environmental concern and increasing awareness among customers, reverse supply chain (RSC) has received much attention among researchers and practitioners. Therefore it is necessary to provide a comprehensive list of references for other researchers (or readers), who are interested in RSC research to help stimulate further interest. In this paper, we present classification schemes and a simple analysis for the reverse supply chain. This literature review was mainly based on journal articles but also included web based documents, conference materials, working papers, etc. A total of 543 articles were reviewed, of which 506 were published between 1967 and 2008 from 100 reputed international journals. Based on the literature review carried out and the nature of research observed in RSC, we have introduced two classification schemes to systematically organise the published articles. The first classification scheme is based on the content related issues on RSC and the second one is based on the solution methodology followed by the researchers. These classification schemes indicate that there is considerable research potential for RSC. The results also show that there is strong growth in RSC research.     

Eco-efficiency in logistics: a case study on distribution network design

Sustainability demands that managers deliberate effects on stakeholders and the environment alongside traditional profitability measures. This paper presents a case study suggested by the managers of a distribution firm that seeks to balance environmental impact with cost in an industrial distribution network configuration decision incorporating product returns, which is currently taking place. While this can be modelled using mathematical programming, nonlinear terms in the objective functions as well as the likeliness that a large number of combinations of binary decision variables result suggest that this will not be able to be relied upon for a solution. For this reason, we propose a heuristic that aims at finding the Pareto-efficient frontier, which managers can use to deliberate the best solution balancing cost and environmental impact, according to the relative trade-offs of various possible configurations. We illustrate this heuristic on the Italian region of Liguria, and further explore trade-offs juxtaposing the regions of Lombardi and Sicily. Lastly, various extensions for enhanced product recovery opportunities for returns are suggested.     

Two-echelon closed-loop supply chain deterministic inventory models in a batch production environment

This paper considers a two-echelon closed-loop supply chain consisting of a manufacturer and a remanufacturer at the upper echelon and a retailer at the lower echelon. The retailer faces a constant demand from customers, which is satisfied through recovered and new products received from the remanufacturer and the manufacturer, respectively. The manufacturer produces the product with finite rate, whereas the recovery of returned product is instantaneous at the remanufacturer. We develop three models to determine the optimal production-inventory policy of the players for minimizing the joint total cost of the system. In the first model, the retailer receives the product in batches from the manufacturer and the remanufacture simultaneously, whereas in the second and third models, the batches are received alternatively. In the third model, however, the procurement of raw material at the manufacturer is also considered. Numerical illustration is presented to examine the impact of certain key parameters.     

Application of QFD for enabling environmentally conscious design in an Indian rotary switch manufacturing organisation

Many businesses are recognising that environmental consciousness is an important concept for survival in today's highly competitive market. This paper presents a project in which quality function deployment (QFD) for environment (QFDE) has been applied to an Indian rotary switch manufacturing organisation to enable environmentally conscious design at the early stage of product development. QFDE consists of four phases. QFDE phases I and II are concerned with the identification of the rotary switch parts that are important in enhancing environmental consciousness. QFDE phases III and IV are concerned with the evaluation of the effect of design improvement on environmental quality requirements. The results obtained from the case study revealed that QFDE could be applied in the early stage of rotary switch product development as it identified the vital components from an environmental perspective and enabled the options for design improvement to be effectively evaluated. The managerial implications of the case study have also been presented.     

A multi-path routing-inventory problem for a closed-loop supply chain considering the heterogeneous fleet of vehicles

In this paper, the inventory-routing problem is studied for a closed-loop supply chain. This closed-loop supply chain considers suppliers, manufacturers, whole-sellers, and disposal centers. To formulate this problem, a mixed integer linear programming model is proposed. This mathematical model minimizes the total costs of the supply chain, including the fixed and variable costs of vehicles, and holding inventory costs of final products and scraps. The proposed model considers the road roughness degree, multi-path setting and the heterogeneous fleet of vehicles, which increases its flexibility and the quality of solutions. Then, two symmetry-breaking constraints are proposed to reduce the complexity of the mathematical model. In order to evaluate the integrity of the proposed model, 20 instances of different sizes are randomly generated and solved. Finally, a comprehensive sensitivity analysis is conducted with respect to five key features of the problem, such as the impact of the symmetry-breaking constraints on the CPU time, multi-path setting, fixed cost of vehicles, heterogeneous fleet of vehicles, and lost sales. The results indicate that the consideration of multi-path setting and the heterogeneous fleet of vehicles improves the quality of solutions significantly.     

Pollution prevention in the pharmaceutical industry

The pharmaceutical industry traditionally uses complex batch-type processes in the manufacture of medicines, although the production of specific medicines by continuous processes is currently envisaged. Due to the diversity of these processes, it is difficult to define a general set of waste prevention guidelines that would apply to all drug manufacturing. The most applicable methods of prevention can, however, be delineated for each of the five steps in the pharmaceutical manufacturing, i.e. (i) research and development, (ii) chemical synthesis, (iii) natural product extraction, (iv) fermentation and (v) product formulation. Waste streams generally arise from cleaning and sterilising equipment, chemical spills, rejected by-products and the processes themselves. Prevention mainly involves waste reduction by materials substitution, process modification/optimisation, waste stream segregation and solvent waste recycling. These measures are assessed and lead to guidelines for waste minimisation methods according to the waste streams under scrutiny.     

Developing a fuzzy linear programming model for locating recovery facility in a closed loop supply chain

In this research a closed loop supply chain is designed which incorporates reverse logistics and forward logistic system simultaneously. In the design of reverse logistic system, recovery options are embedded in traditional supply chain for treating returned products. The recovery system includes collection centres, remanufacturing plants and disposal centres. Since the product return is supply driven, there is an uncertainty about it. In the proposed configuration for closed loop supply chain, the optimised configuration for supply chain in terms of locating recovery plants is developed. Accordingly, a fuzzy mixed integer linear programming model develops to deal with the uncertainty of returning products by customers. A general-purpose solver (LINGO 8.0) and a Meta heuristic approach (genetics algorithm) are implemented to solve the proposed model. The answers are compared by defining indexes and then the optimal answer, configuration and variables are identified. This solution will suggest a new design of supply chain network in which waste of materials is minimised and the new raw materials are necessary only when the used products may not be recovered by recovery options.     

Supplier evaluation and selection for sustainable supply chain management under uncertainty conditions

Abstract

With the global increasing importance of sustainable development, sustainable supply chain has gained value among both researchers and industrialists in the last decade. Nowadays, industries are facing pressure from government legislation and the global competition in addition to the pressure from their clients to carry out environmentally – conscious actions. Thus, organisations are required to implement actions to enhance their level of both environmental and economic performances. Traditionally, organisations use criteria such as cost, quality and on-time delivery to evaluate their suppliers’ performance. Although there have been numerous studies on the common criteria for these assessments, very few studies have taken sustainable criteria into consideration. Thereupon, this study tries to put forward a complete model for selection and evaluation of the suppliers, considering three criteria for sustainability, thus using the fuzzy group graph theory and matrix approach. It is an innovative approach based on fuzzy logic and group decision-making, which aims to treat lack of certainty in selection and evaluation of suppliers. We will also discuss a case study in the industry to demonstrate the effectiveness of our proposed approach.     

Recycling – the importance of understanding the complexity of the issue

Natural resources and raw materials such as metals and minerals are often taken for granted in today’s society. Without them, the offerings of an enormous variety of modern conveniences, including computers and mobile phones, would not be possible. The production of these everyday items depends on a secure, sustainable, and reliable supply of critical raw materials. In addition, product development also requires new hybrid materials when targeting lightweight structures, etc. However, the mandatory recyclability of new products or materials is not obligatory or even prevailing practice in present manufacturing business. Therefore, the main research question in this article is: “how to solve the challenge of recycling in industrial system?” In this article, a comprehensive approach to recycling based on the findings of research projects is presented. Simplified, this involves moving the challenge from the end of the product’s life cycle to the beginning, to the design or even to material development phases. Life cycle and system thinking and material know-how in the design phase are found to be essential elements of a new approach to recycling. This approach stems from the material development and market economy perspectives. Furthermore, the vulnerability of the industrial system to create uncertainty to recycling is also demonstrated.     

中国高速铁路运营的减碳及经济环境互馈影响研究

二氧化碳等温室气体排放备受世界关注,新形势下低碳发展成为中国发展路径的新选择,而高速铁路是长距离运输低碳化的具体体现。基于运营阶段的行车碳排放换算,综合考虑多种交通工具的实际运载能力、标准运行速度等指标,分析中国高速铁路行车运营的减碳效果及经济环境互馈影响。研究发现:(1)以单位运输能耗量及该能源的碳排放系数计算,中国高速铁路行车与其余交通运输方式相比具有显著减碳效果,其百公里人均碳排放量约为航空运输的1/5和高速公路运输的1/3,且随着中国能源结构的逐步优化,减碳效果将会愈发凸显。(2)结合中国旅客周转量比例进行折算,自2008年至2015年高速铁路运输累计减碳2 610万t,从空间上看,省域差距明显,高速铁路运输繁忙的京沪线及京广线沿线地区,成为2015年高速铁路行车运营减碳效果的高值区,亦由此呈现出带状聚邻的正空间自相关性。(3)高速铁路运营产生经济环境的良性互馈影响,一方面环境优化具有潜在经济效益,2008—2015年的减碳效果相当于降低碳交易成本逾10亿元,其绿色设计及应用也益于区域经济发展;另一方面高速铁路运营经济收益具有潜在环境补偿能力,2008—2015年累计对区域节能环保支出贡献逾30亿元,其中高值区以中国中部地区为主,空间分布呈斜T字型结构,其成因与地区节能环保支出占比、出行结构等因素相关。基于上述分析并结合中国发展的客观实际,提出合理增强高速铁路运输效能、继续优化能源供给结构等优化对策,以期从出行视角为中国低碳发展提供交通领域的理论支撑。     

1949年以来中国环境与发展关系的演变

从IPAT方程出发,发现了环境影响随着经济发展或时间的演变依次遵循三个"倒U型"曲线规律,即环境影响强度的倒U型曲线、人均环境影响的倒U型曲线和环境影响总量的倒U型曲线。根据此规律,可以将该演化过程划分为四个阶段即:环境影响强度高峰前阶段、环境影响强度高峰到人均环境影响量高峰阶段、人均环境影响量高峰到环境影响总量高峰阶段以及环境影响总量稳定下降阶段。在环境演变的不同阶段,主要驱动力存在着明显的差异。在环境影响强度高峰前阶段,资源消耗或污染物排放增长更多地由资源或污染密集型技术进步驱动;在资源消耗或污染物强度高峰到人均资源消耗或污染物排放高峰阶段,主要由经济增长驱动;而在人均资源消耗或污染物排放高峰到资源消耗或污染物排放总量高峰阶段以及总量高峰以后的发展阶段,则主要由节约高效技术或污染减排技术进步来驱动。实证分析表明,中国目前环境与发展关系基本上处于经济增长主要驱动的环境影响强度高峰向人均环境影响高峰过渡阶段,这同时意味着中国要在短期内实现人均环境影响和环境影响总量高峰的跨越是异常困难的。