Modelling green and lean supply chains: An eco-efficiency perspective
مدل سازی زنجیره تامین سبز و ناب: چشم انداز سازگار با محیط زیست بهره وری-2017
This manuscript proposes a model to support decision making and to help managers identify the best set of green and lean supply chain management practices to improve their eco-efficiency. To attain this objective, a mathematical model based on eco-efficiency concepts is suggested to overcome the trade-offs between lean and green practices. To illustrate the model application, a case study from an automotive supply chain is presented. Some management practices that are instituted for green or lean benefits have opposite effects on the environmental and economic performance of companies. One of the main findings of our study is that not all companies belonging to the same supply chain can be absolutely lean or green. There should be compromises in the individual companies’ behaviour so the environmental and economic constraints of the supply chain are both satisfied. The proposed model represents a strategic framework to support the design of eco-efficient supply chains.
Keywords: Eco-efficiency | Lean | Green |Supply chain |Linear programming model
A Decision Support Tool for the Strategic Assessment of Transport Policies – Structure of the Tool and Key Features
یک ابزار پشتیبانی تصمیم برای ارزیابی استراتژیک سیاست های حمل و نقل - ساختار ابزار و ویژگی های کلیدی-2017
Decisions on transport policy measures proposed by the European Union (EU) have long-term and important impacts on economy, environment and society. Transport policy measures can lock up capital for decades and cause manifold external effects – thus, policy measures may have a tremendous scope, especially if proposed on a European level. In order to allow European policy-makers to evaluate transport polices, a strategic assessment tool is required to compute economic, environmental and social impacts of transport policies. The paper illustrates the conceptual phase of development of the strategic high-level transport policy assessment instrument HIGH-TOOL. After careful identification of user requirements, on the basis of EU policy documents and user surveys, the conception stage of the strategic transport policy assessment tool is described in terms of tool structure, scope of output indicators, transport policies covered and other key features. Besides elaborating the structure and key features of the assessment instrument, the paper demonstrates the complexity and sensitivity associated with the conception stage of the development of a policy assessment tool. Several targets of a policy assessment tool are mutually conflicting, which results in the need to carefully counter-balance these targets, under consideration of methodological and implementation-wise aspects. The paper elaborates trade-offs between different tool objectives and derives a magical polygon of targets of an assessment instrument. After careful identification of user requirements, on the basis of EU policy documents and user surveys, the conception stage of the strategic transport policy assessment tool is described in terms of tool structure, scope of output indicators, transport policies covered and other key features. Besides elaborating the structure and key features of the assessment instrument, the paper demonstrates the complexity and sensitivity associated with the conception stage of the development of a policy assessment tool. Several targets of a policy assessment tool are mutually conflicting, which results in the need to carefully counter-balance these targets, under consideration of methodological and implementation-wise aspects. The paper elaborates trade-offs between different tool objectives and derives a magical polygon of targets of an assessment instrument.
Keywords:impact assessment | transport policy | economic | environmental | social impacts | assessment tool | European Union | model | decision support | model conception
Closing loops in agricultural supply chains using multi-objective optimization: A case study of an industrial mushroom supply chain
حلقه بسته شدن در زنجیره تامین کشاورزی با استفاده از بهینه سازی چند منظوره: مطالعه موردی زنجیره تامین قارچ صنعتی-2017
Environmental concerns and scarcity of resources encourage decision makers in supply chains to con sider alternative production options that include preventing the production of waste streams, and si multaneously reusing and recycling waste materials. Until now, hardly any quantitative modeling ap proaches exist in literature on closing loops in agri-food supply chains. In contrast to closed-loop studies in discrete parts industry, in agri-food supply chains the value of the final product itself cannot be re gained. However, the components used for production such as organic matter or a growing medium, can be recycled. In this paper, the consequences of closing loops in a mushroom supply chain are revealed. We propose a multi-objective mixed integer linear programming model to quantify trade-offs between economic and environmental indicators and explore quantitatively alternative recycling technologies. The model was developed to re-design the logistical structure and close loops in the mushroom supply chain. We found that adopting closing loop technologies in industrial mushroom production has the potential to increase total profitability of the chain by almost 11% while the environmental performance improves by almost 28%. We conclude that a comprehensive evaluation of recycling technologies and re designing logistical structures requires quantitative tools that optimize simultaneously managerial de cisions at strategic and tactical level.
Keywords: Multi-objective optimization | Linear programming | Closed loop supply chain | Exergy | Champignon production
Green supply chain design: A mathematical modeling approach based on a multi-objective optimization model
طرح زنجیره تامین سبز: رویکرد مدل سازی ریاضی بر اساس یک مدل بهینه سازی چند هدفه-2017
Increasing levels of industrialization of developed nations associated with globalization trends have been creating new challenges to supply chain management (SCM). For decades, the main focus of SCM has been on efficient ways of managing the flows through complex networks of supplier, producers and customers. More recently, and as a result of the exponential increase of energy and materials con sumption rates of energy and materials, sustainable development arise as an urgent issue and new ap proaches to SCM are required to incorporate environmental and economic concerns in the design of supply chains. In this paper, a new green supply chain (GSC) design approach has been proposed to deal with the trade-offs between environmental and financial issues in order to reduce negative impacts on the environment caused by the increasing levels of industrialization. The new approach incorporates a closed loop network to accommodate the reprocessing paradigm of disposal products and a multi-ob jective optimization mathematical model to minimize overall costs and carbon dioxide emissions when setting the supply chain. Optimization process is performed using three scalarization approaches, namely weighted sum method, weighted Tchebycheff and augmented weighted Tchebycheff. Computational results are analyzed to identify the advantages and drawbacks of each approach. The model was tested in a case study and results allowed to identify the capability of the model to deal with the trade-offs be tween the costs and environmental issues as well as to identify its main limitation when addressing real size problems.
Keywords: Green supply chain | Closed loop network | Multi-objective optimization | Weighted sum method | Tchebycheff approach
پیاده سازی "اهداف توسعه پایدار": در راستای رسیدگی به سه چالش اصلی حاکمیتی- اقدام مشترک، توافق ها و پاسخگویی
سال انتشار: 2017 - تعداد صفحات فایل pdf انگلیسی: 7 - تعداد صفحات فایل doc فارسی: 16
تحقق آرزوهای "اهداف توسعه پایدار" (SDGs) برای کاهش نابرابری، کاهش آسیب زیست محیطی، و تامین معیشت انعطاف پذیر، یک چالش بزرگ برای علم پایداری، جامعه مدنی و دولت است. ما سه چالش اصلی حاکمیتی را برای اجرای SDG ها شناسایی می کنیم: (i) ترویج اقدام مشترک با ایجاد فضاهای تصمیم گیری فراگیر برای تعامل متقابل بین بخش ها و معیار های مختلف؛ (ii) ایجاد توافقات سخت، تمرکز بر برابری، عدالت و انصاف؛ و (iii) اطمینان از مکانیزم های موجود برای انجام فعالان اجتماعی برای تصمیم گیری، سرمایه گذاری، اقدامات و نتایج. این مقاله هر یک از این سه چالش حاکمیتی را توضیح می دهد و راه های ممکن برای رسیدگی به آنها را مشخص کرده و اهمیت ارتباط بین این سه چالش را برجسته می نماید.
|مقاله ترجمه شده|
The fuzzy multi-objective distribution planner for a green meat supply chain
برنامه ریزی توزیع چند منظوره فازی برای یک زنجیره تامین گوشت سبز-2017
It is often a complex task for developing a product distribution plan of a supply chain (SC) network and a supportive decision tool can be useful for easing the role of decision-making. On the other hand, it has been increasingly becoming a demand to design a supply chain network considering the environmental impact as a new dimension as required by authorities in many countries. This paper describes a development of a product distribution planner for a three-echelon green meat supply chain (MSC) design in terms of issues including numbers and locations of facilities that should be opened in association with the product quantity flows. These issues were formulated into a fuzzy multi-objective programming model (FMOPM) with an aim to minimize the total cost of transportation and implementation, the amount of CO2 emissions in transportation and the distribution time of products from farms to abattoirs and from abattoirs to retailers, and maximize the average delivery rate in satisfying product quantity as requested by abattoirs and retailers. To optimize the four objectives simultaneously, three solution methods were investigated and used; which are the LP-metrics method, the ε-constraint method and the goal programming method. The best solution was determined using the Max-Min method by comparing the obtained Pareto solutions. A case study was examined based on the developed model that demonstrates its applicability in making an optimal product distribution plan in trade-offs among the four objectives.
Keywords: Distribution plan | Food supply chain design | Fuzzy multi-objective programming |Green supply chain |RFID
Parallel cut tree algorithms
الگوریتم درخت برش موازی-2017
A cut tree is a combinatorial structure that represents the edge-connectivity between all pairs of vertices of an undirected graph. Cut trees solve the all pairs minimum s–t-cut problem efficiently. Cut trees have a large number of applications including the solution of important combinatorial problems in fields such as graph clustering and graph connectivity. They have also been applied to scheduling problems, social network analysis, biological data analysis, among others. Two sequential algorithms to compute a cut tree of a capacitated undirected graph are well known: the Gomory–Hu algorithm and the Gusfield algorithm. In this work three parallel cut tree algorithms are presented, including parallel versions of Gusfield and Gomory–Hu algorithms. A hybrid algorithm that combines techniques from both algorithms is proposed which provides a more robust performance for arbitrary instances. Experimental results show that the three algorithms achieve significant speedups on real and synthetic graphs. We discuss the trade-offs between the alternatives, each of which presents better results given the characteristics of the input graph. On several instances the hybrid algorithm outperformed both other algorithms, being faster than the parallel Gomory–Hu algorithm on most instances.
Keywords: Graph edge-connectivity | Cut tree algorithms | Parallel algorithms
ATM performance measurement in Europe, the US and China
اندازه گیری عملکرد دستگاه خودپرداز در اروپا، ایالات متحده و چین-2017
Air traffic management (ATM) performance and the metrics used in its assessment are investigated for the first time across the three largest ATM world regions: Europe, the US and China. The market structure and flow management practices of each region are presented. A wide range of performance data across these three regions is synthesised. For topological and performance assessment, the notion of a ‘sufficient’ sample is often non-intuitive: many metrics may behave non-monotonically as a function of sampling fraction. Missing and under-developed metrics are identified, and the need for a balance between standardisation and flexibility is proposed. Longitudinal and cross-sectional metric trade-offs are identified.
KEYWORDS : Air traffic management | Data | Metric | Performance | Sampling | Topology
A robust optimization approach for airport departure metering under uncertain taxi-out time predictions
رویکرد بهینه سازی قوی برای اندازه گیری خروج فرودگاه تحت پیش بینی زمان نا مشخص تاکسی-2017
Airports are critical elements in the air transportation system in terms of traffic flow management. The high volume of operations along with the constraining airside capacity can exacerbate surface congestion and lead to increased flight delays and costs, especially during peak times. Surface traffic optimization is an alternative for alleviating congestion. However, the high level of uncertainty in actual operations can compromise the effectiveness of optimal policies. This paper presents a robust optimization approach for metering aircraft departures under uncertainty in the taxi-out process. A mixed integer linear programming model for runway sequencing and scheduling that incorporates uncertainty sets for the taxi-out time is proposed in order to dynamically determine an optimal and robust sequence and schedule of aircraft release from the gate. Actual operational data from Brasilia International Airport in Brazil is used to evaluate the effectiveness of departure metering at this airport. An assessment of benefits and trade-offs of introducing robustness is performed based on stochastic simulation of departure performance under different control strategies. The robust optimization approach shows positive impacts in protecting against uncertainty as it reduces runway delays and taxi-out times and increases takeoff time predictability.
Keywords: Air traffic flow management | Air traffic control | Departure metering | Robust optimization
Multi-period planning of closed-loop supply chain with carbon policies under uncertainty
برنامه ریزی چند مرحله ای زنجیره تامین حلقه بسته با سیاست های کربن در شرایط عدم اطمینان-2017
Climate change and greenhouse gases emissions have caused countries to implement var ious carbon regulatory mechanisms in some industrial sectors around the globe to curb carbon emissions. One effective method to reduce industry environmental footprint is the use of a closed-loop supply chain (CLSC). The decision concerning the design and plan ning of an optimal network of the CLSC plays a vital role in determining the total carbon footprint across the supply chain and also the total cost. In this context, this research pro poses an optimization model for design and planning a multi-period, multi-product CLSC with carbon footprint consideration under two different uncertainties. The demand and returns uncertainties are considered by means of multiple scenarios and uncertainty of car bon emissions due to supply chain related activities are considered by means of bounded box set and solve using robust optimization approach. The model extends further to inves tigate the impact of different carbon policies such as including strict carbon cap, carbon tax, carbon cap-and-trade, and carbon offset on the supply chain strategic and operational deci sions. The model captures trade-offs that exist among supply chain total cost and carbon emissions. Also, the proposed model optimizes both supply chain total cost and carbon emissions across the supply chain activities. The numerical results reveal some insightful observations with respect to CLSC strategic design decisions and carbon emissions under various carbon policies and at the end we highlighted some managerial insights.
Keywords:Closed-loop supply chain network design|Carbon policies|Carbon emission|Transportation mode selection|Mathematical modelling|Stochastic |programmingRobust optimization