系统动力学的碳排放政策对供应链影响

随着低碳经济的发展,碳排放政策对于供应链的影响越来越受到关注。建立了基于系统动力学的单个供应商和销售商的供应链模型,并在此基础上引入强制排放和碳税两种碳排放政策。利用模型仿真,分析两种排放政策对于供应商、销售商及整个供应链的总成本和碳排放的影响。研究表明在强制排放模型中,不同的碳排放额度会使销售商选择不同的订货周期,发现合理的排放额度才能引导供应链双方降低排放,否则不仅达不到减排的目的,反而影响供应链效率;而在碳税模型中,提高碳税税率虽然会使政府获取一定的收益,但是实际上可能带来供应链总成本的上升和碳排放的增加,需要合理制定碳税税率引导绿色供应链发展。     

Operational and environmental decisions for a two-stage supply chain under vendor managed consignment inventory partnership

Supply-chain-based organisations are nowadays facing intense pressure to abide to environmental regulatory requirements while they are striving to be responsive to customers’ needs at the least cost possible. As supply chain activities are among the top contributors to carbon emissions, several recent research works have investigated the impact of carbon regulation policies on economic and environmental supply chain performance. This paper presents integrated economic and environmental models for the one-vendor one-buyer supply chain problem under a vendor managed consignment inventory (VMCI) arrangement. Through the developed models, we study the impacts of two carbon reduction policies, namely carbon cap and carbon tax policies, on supply chain wide costs and carbon emissions. We first provide a much simpler and more compact formulation for the basic single-vendor single-buyer supply chain under VMCI agreement. We also present an environmental-based VMCI model where reduction of carbon footprint is considered as the only objective function. We then extend these two basic models to include each of the two carbon emissions reduction policies. We identify structural properties for the optimal solutions of the two hybrid economic and environmental models and propose algorithms to generate optimal solutions. The results of the computational experiments reveal that the implementation of carbon reduction policies, through carbon cap and carbon tax, may call for the adjustment of the vendor’s production and buyer’s delivery quantities to reduce carbon footprint without significantly increasing the operational costs.     

考虑碳税征收的供应链纵向减排博弈研究

在低碳经济背景下引入碳排放税及消费者低碳偏好,对供应商主导的二级供应链减排博弈展开研究;进而通过逆向归纳法求得序贯行动的精炼子博弈纳什均衡,并采用数值实验展开分析。研究表明,在外生碳税下供应商和制造商都将采取减排策略,可求得最优产量与单位产品减排量,但征收碳税并不一定能够保证碳排放总量的降低;供应链中一方的减排行为将激励另一方增加单位产品减排量;企业减排成本系数越低,征收碳税对控制碳排放总量的效果越明显。     

An optimization study of a palm oil-based regional bio-energy supply chain under carbon pricing and trading policies

Biomass residues due to their low bulk density typically require frequent transportation from biomass plantations in rural areas to conversion bio-energy power plants. This issue contrasts with environmental protection strategies, especially when power plants are facing different carbon reduction policies that enforce them to emit less than a given specific carbon amount. Although several researchers have investigated bio-energy supply chains concerning environmental policies, the majority of studies have been devoted to strategic decisions over a single planning period. This paper presents a multi-period bio-energy supply chain under carbon pricing (carbon tax) and carbon trading (cap-and-trade) policies at the tactical planning level. A mixed-integer linear programming model was adopted to optimize the proposed regional oil-palm biomass-to-bio-energy supply chain planning model. The numerical results indicate that when carbon pricing is in place when carbon tax increases linearly, carbon emissions’ reductions have a nonlinear trend, whereas both cost increase and carbon emissions’ reductions have a relatively upward trend in the carbon trading scheme. This paper also presents the sensitivity analysis of the proposed model regarding cost, emissions’ generation and supply chain performance. Finally, the paper recommends several significant practical implications and policy-making insights for managers and policymakers.     

A blockchain-based approach for a multi-echelon sustainable supply chain

Blockchain technology is destined to revolutionise supply chain processes. At the same time, governmental and regulatory policies are forcing firms to adjust their supply chains in response to environmental concerns. The objective of this study is therefore to develop a distributed ledger-based blockchain approach for monitoring supply chain performance and optimising both emission levels and operational costs in a synchronised fashion, producing a better outcome for the supply chain. We propose the blockchain approach for different production allocation problems within a multi-echelon supply chain (MESC) under a carbon taxation policy. As such, we couple recent advances in digitalisation of operations with increasingly stringent regulatory environmental policies. Specifically, with lead time considerations under emission rate constraints (imposed by a carbon taxation policy), we simultaneously consider the production, distribution and inventory control decisions in a production allocation-based MESC problem. The problem is then formulated as a Mixed Integer Non-Linear Programming (MINLP) model. We show that the distributed ledger-based blockchain approach minimises both total cost and carbon emissions. We then validate the feasibility of the proposed approach by comparing the results with a non-dominated sorting genetic algorithm (NSGA-II). The findings provide support for policymakers and supply chain executives alike.     

Uncertain supply chain network design considering carbon footprint and social factors using two-stage approach

Sustainable development has become one of the leading global issues over the period of time. Currently, implementation of sustainability in supply chain has been continuously in center of attention due to introducing stringent legislations regarding environmental pollution by various governments and increasing stakeholders’ concerns toward social injustice. Unfortunately, literature is still scarce on studies considering all three dimensions (economical, environmental and social) of sustainability for the supply chain. An effective supply chain network design (SCND) is very important to implement sustainability in supply chain. This study proposes an uncertain SCND model that minimizes the total supply chain-oriented cost and determines the opening of plants, warehouses and flow of materials across the supply chain network by considering various carbon emissions and social factors. In this study, a new AHP and fuzzy TOPSIS-based methodology is proposed to transform qualitative social factors into quantitative social index, which is subsequently used in chance-constrained SCND model with an aim at reducing negative social impact. Further, the carbon emission of supply chain is estimated by considering a composite emission that consists of raw material, production, transportation and handling emissions. In the model, a carbon emission cap is imposed on total supply chain to reduce the carbon footprint of supply chain. To solve the proposed model, a code is developed in AMPL software using a nonlinear solver SNOPT. The applicability of the proposed model is illustrated with a numerical example. The sensitivity analysis examines the effects of reducing carbon footprint cap, negative social impacts and varying probability on the total cost of the supply chain. It is observed that a stricter carbon cap over supply chain network leads to opening of more plants across the supply chain. In addition, carbon footprint of supply chain is found to be decreased in certain extent with the reduction in negative social impacts from suppliers. The carbon footprint of the supply chain is found to be reduced with increasing certainty of material supply from the suppliers. The total supply chain cost is observed to be augmented with increasing probability.     

Joint decisions on inventory replenishment and emission reduction investment under different emission regulations

Carbon emission regulation policies have emerged as mechanisms to control firms’ carbon emissions. To meet regulatory requirements, firms can make changes in their production planning decisions or invest in green technologies. In this study, we analyse a retailer’s joint decisions on inventory replenishment and carbon emission reduction investment under three carbon emission regulation policies. Particularly, we extend the economic order quantity model to consider carbon emissions reduction investment availability under carbon cap, tax and cap-and-trade policies. We analytically show that carbon emission reduction investment opportunities, additional to reducing emissions as per regulations, further reduce carbon emissions while reducing costs. We also provide an analytical comparison between various investment opportunities and compare different carbon emission regulation policies in terms of costs and emissions. We document the results of a numerical study to further illustrate the effects of investment availability and regulation parameters.     

改进麻雀算法求解带模糊需求的低碳路径优化

目的 针对低碳背景下带模糊需求的低碳多式联运规划问题（Low-carbon Multimodal Transportation Planning Problem with Fuzzy Demand, LCMTPP-FD），以成本最小化构建数学模型。同时，结合现有的强制碳排放、碳税、碳交易和碳补偿等政策对LCMTPP-FD进行模型转换，研究不同低碳政策对物流成本和碳排放量的影响。方法 主要根据模型的特征，设计一种t分布麻雀搜索算法，对不同低碳政策下的模型进行求解，将迭代次数作为t分布的自由度来提高麻雀算法的性能。结果 将改进算法及多个模型应用于实际运输案例中，改进的麻雀算法能在较短时间内获得最优解，并且在强制碳排放下碳排放量最少为9 522.28，在碳交易和碳补偿政策下成本分别降低了11.41%、17.24%。结论 改进的麻雀搜索算法具有较好的收敛性和搜索能力。强制碳排放能有效地降低碳排放量，碳交易和碳补偿能有效降低企业成本，适合于低碳运输的推广。     

Effects of carbon emission regulations on remanufacturing decisions with limited information of demand distribution

Policy-makers are developing regulation policies to drive down carbon emissions from industries. Independent remanufacturers (IRs), which remanufacture recycled products/components/parts, must manage and evaluate economic costs generated by the production under future carbon emission regulations. We present three optimisation models to determine the remanufacturing quantity that maximises the total profits under three common carbon emission regulation policies: (a) mandatory carbon emissions capacity, (b) carbon tax and (c) cap and trade. These models include sales revenue, remanufacturing cost, disposal cost, inventory holding cost, shortage cost and carbon emission cost. The max–min approach is used to solve the models, which assume limited information on demand distribution. We investigate how the three regulation policies affect remanufacturing decision-making for IRs and we also solve some numerical examples where we vary the magnitudes of incentives, penalties and stringency of constraints to provide implications to policy-makers. The results indicate that remanufacturers should aim to improve yield rate to maximise the profit irrespective of the implemented carbon emissions policy. Policy-makers should prefer the carbon tax policy, if any of the other two policies must be performed, a remanufacturing discount such as a higher carbon emission cap or lower penalty should be implemented to better promote the development of remanufacturers.     

考虑运输速度和碳排放的易腐食品供应链网络优化研究

针对易腐食品供应链网络的特征,将运输速度、腐败率考虑在内,建立了一个混合整数非线性（MINLP）模型,利用YALMIP软件求解以达到使整个供应链总成本最少和碳排放量尽量少的目的。最后,通过算例分析证明该模型的可行性,得出碳排放量与车速相关及车辆的最佳运输速度,并利用灵敏度分析,揭示碳单位价格和腐败率的变化对整个供应链的影响。     

冷链物流系统碳足迹模型构建与实证分析

为系统衡量冷链物流的碳足迹问题,本文提出了一种计算冷链物流碳足迹的系统方法并构建了冷链物流系统碳足迹模型。研究以香蕉全程冷链物流碳足迹问题展开实证分析,采用生命周期评估法、投入产出法、碳排放系数法界定冷链物流不同流通环节碳足迹的核算范围,测算了生产、采收处理、预冷及冷藏运输、贮藏、配送作业和终端销售等各环节所产生的碳足迹;运用实际案例对模型优化求解。在本案例中,当系统总成本为354.74万元,对应的系统总碳足迹为148.62 t;当系统总成本为369.21万元时,对应的系统总碳足迹为145.21 t。对冷链物流碳足迹进行敏感性分析,结果表明:碳税的增加能使系统总成本最大程度增加0.8%,而腐损率的上升可使系统总成本和碳足迹以相同的趋势增加约35%,说明该模型可有效测算冷链物流活动中的碳足迹。     

Game-theoretical analysis for supply chain with consumer preference to low carbon

This paper focuses on the impact of consumers’ preference to low carbon in the emission-concerned supply chain. In an emission-concerned supply chain, the consumers are assumed to prefer to low-carbon products. In an emission sensitive market, emission reduction not only brings the higher production costs but also stimulates the inverse demand function. Therefore, this may be an opportunity for players of the supply chain to coordinate their two objectives: environmental pressure (to reduce carbon emissions for environment protection) and profit-seeking, which intuitively seem to be contradictory. In order to address this research focus, a novel emission-sensitive demand function is adopted, and an emission -sensitive cost function is introduced explicitly to capture the deviation production cost caused by emission reduction. Then the decision-making of each member in the emission-concerned supply chain is investigated. We find that the decision-maker of the supply chain will choose different emission reduction strategies for different cases. An inspiring result shows that the channel profit as well as the emission reduction increase in the consumers’ preference to low-carbon consumption simultaneously in particular cases. Moreover, several emission-concerned contracts are designed to coordinate the channel. Another finding is that the manufacturer’s optimal carbon emissions per unit product keeps the same as the centralised channel, no matter whether the supply chain is coordinated or not. Furthermore, the further discussion reveals that less eco-friendly production than the traditional, if lack of external regulation as well as internal moral self-discipline, might be chosen under some specific conditions.     

不确定环境下多目标绿色供应链生产计划模型

针对近年来不断引发关注的工业环境污染问题以及制造业绿色供应链运营困难的问题,本文考虑分销商需求量、生产能力、成本和运输等参数为区间数,以供应链总成本最小、响应时间最短和碳排放量最少为目标,构建不确定环境下的多运输方式、多工厂、多分销商的绿色供应链生产计划模型。利用区间序关系和区间可能度定义给出不确定模型的清晰等价形式,并采用多目标规划方法对模型进行求解。最后通过算例分析可能度水平和区间变化率对企业决策的影响。研究表明,可能度水平较小或区间参数变化率较大时,会使生产条件变得更加宽厚,有利于企业降低供应链总成本。     

碳税情形下考虑低碳偏好的收益共享契约协调模型

研究考虑碳税和消费者具有低碳偏好情形的供应链碳减排的协调问题,得到实现供应链碳减排协调的必要条件。通过引入数量折扣策略,构建供应链碳减排的收益共享契约协调模型,解决纯粹的收益共享契约无法协调供应链碳减排的问题,并给出契约参数需要满足的条件。在消费者的低碳偏好以加法形式来影响市场需求时,通过模型优化,给出供应链的最优产品订购量和最优碳排放水平的确定方法。研究发现,在供应链协调时,供应商提供给制造商的批发价格是碳税的减函数,是碳排放水平的增函数;供应链系统的订购量与碳税成反比,而碳减排水平与碳税成正比,与碳减排系数成反比。     

不同碳排放政策下考虑碳减排投入的供应链协调

在考虑碳减排技术投入下,为了实现不同碳排放政策下的供应链协调,通过建立集中式和分散式决策下的供应链模型,根据供应链协调的条件,给出了供应链实现协调的契约形式及契约参数。为了确定不同碳排放政策下的最优订货量和最优碳减排率,通过对博弈模型进行优化,提出了具体的求解方法。数值计算结果表明：随着碳排放政策的变化,供应链的最优订货量、最优碳减排率和供应链的利润也将发生相应的变化,而生产成本、缺货损失、产品残值、销售价格、批发价格等参数变化不仅会影响最优订货量、最优碳减排率和供应链利润,还会影响收益共享比例、碳减排技术投入和碳排放成本的分摊比例。     

考虑残次品和碳排放的供应链多级库存的EOQ模型

针对供应链多级库存系统,探析残次品与碳排放对该系统的影响作用与供应链库存持有成本、订购成本、运输成本和检查成本的构成函数,建立多级库存的EOQ模型,提供考虑残次品和碳排放的供应链订货经济批量和库存控制策略,并用算例验证了模型的有效性。     

二级物资供应系统中不同应急调货策略的比较分析

主要研究物资供应系统中两种应急调货策略的效果。考虑一个二级多点的供应系统,需求随机产生,针对两种策略分别建立相应模型计算各项系统指标,用数值模拟对两种策略的效果进行比较。结果表明,允许转运的应急调货策略可以显著降低系统总成本。     

随机需求下半开放式冷链物流车辆路径优化

目的 降低冷链物流配送成本的同时,保证客户体验及碳排放达到企业要求。方法 综合考虑运输距离、客户软时间窗约束、碳排放、生鲜变质等因素,以制冷成本及对配送时间惩罚成本在内的总成本最低、碳排放量最低、生鲜产品新鲜度最高为目标,建立多目标生鲜配送路径优化模型,并设计模拟退火算法,以北京某冷链物流企业为例进行求解验证。结果 得出生鲜配送方案,通过配送模式对比表明多中心半开放式在降本和缩短路径长度方面更具优势,其中运输总费用和车辆行驶总距离相比于单中心独立配送模式分别降低了8.41%和36.36%。结论 需求不确定下,合理决策路由可在达到企业对生鲜产品新鲜度及碳排放标准的同时,有效降低配送成本。     

碳政策下货运企业运营成本比较分析

考虑两种碳政策：碳交易、碳税,研究其对货运物流企业运营成本的影响。以总成本最小为目标,考虑车辆油耗与其载货重量的关系以及减少固定碳排放需要付出一定的机会成本,构建两阶段车辆路径优化模型,并设计遗传算法求解。数值分析显示两种碳政策的实施均增加了企业的经营成本,但促使企业减少碳排放;货运企业可以从两方面减少碳排放：1）减少固定碳排放,例如减少办公能耗与员工出差等;2）优化车辆性能,降低车辆的百公里综合油耗与提高车辆排放标准。     

Financing Strategy of Low-Carbon Supply Chain with Capital Constraint under Cap-and-Trade Regulation

Cap-and-trade regulation provides incentives for manufacturers to reduce carbon emissions, but manufacturers’ insufficient capital can disrupt the implementation of low-carbon emission reduction technologies. To alleviate capital constraints, manufacturers can adopt external financing for low-carbon emission reduction investments. This paper studies the independent financing and financing cooperation behavior in a supply chain in which the manufacturer and retailer first implement low-carbon emission reduction technologies and then organize production and sales in accordance with wholesale price contracts. Through comparing the optimal profits and low-carbon emission reduction levels under the independent financing and financing cooperation mode, we come to the following conclusions: (1) Although financing interest increases the cost of the supply chain, manufacturers prefer to invest in reducing carbon emissions rather than buying carbon quotas. (2) When financing independently, a decentralized decision-making mode (MD) is the best choice for manufacturers. (3) In cooperative financing, when the supply chain adopts a decentralized decision-making mode (SD) in which the retailer determines the financing cost-sharing ratio according to their optimal profit, the profits of the supply chain and its members are significantly improved. (4) When manufacturers and retailers adopt a centralized decision-making model (SC) in cooperative financing, they jointly determine the financing cost-sharing ratio and the level of low-carbon emission reduction. If the financing cost-sharing ratio meets a certain threshold range, the profits of manufacturers and retailers achieve Pareto improvement, indicating that this cooperative financing model is effective.