Chain Design Research Articles

Áreas clave para la alineación de la agilidad y resiliencia con la perspectiva de género en las organizaciones

La equidad de género en las organizaciones es un aspecto cada vez más necesario y demandado por la legislación; implica satisfacer el derecho constitucional de la igualdad. Hasta ahora, en su estudio, no se ha tenido en cuenta aspectos como agilidad y resiliencia. El presente artículo propone la definición preliminar de un modelo de madurez que permita evaluar la incorporación de la perspectiva de género sin limitar la agilidad y resiliencia en la organización, extrayendo la relación que indique qué aspectos de agilidad y resiliencia pueden verse afectados por las áreas donde la perspectiva de género debe ser incorporada.

Multi-objective green supply chain network optimization

Abstract
 
 In supply chain management, economical objectives have traditionally guided decisions of the supply chains. However, with increased global environmental and social concerns, in recent years, green aspects have been incorporated in supply chain decisions. These expansions lead to new research areas about green or sustainable supply chain management that includes applying various green practices in order to reduce negative impact on the environment or providing sustainable development. The purpose of this study is to develop a multi-objective optimization model for determining network design of the green supply chains. In multi-objective frame of the proposed model, total profit maximization and environmental impact minimization objectives are considered in order to obtain best network configuration for economic and environmental performance of the green chain. The proposed model is validated with numerical experiments. Obtained results showed that the model can be used as a strategic decision tool in problems with multi and conflicting objectives.
 Keywords: green supply chain management, multi-objective modelling, network optimization.

Supply chain solutions to improve the distribution of antiretroviral drugs (ARVs) to clinics in rural areas: A case study of the QwaQwa district

This article serves as a case study based on research that was performed in the QwaQwa district in the Free State Province where the distribution of ARVs to the regional Manapo hospital, as well as between the hospital and its peripheral clinics, was interrupted and inconsistent due to problems in the supply chain. An unreliable and interrupted ARV supply chain creates the risk of virus reactivation and eventual patient mortality.The objectives of the study were to explore the problems experienced with the ARV distribution practices at the Manapo hospital, and to recommend ways in which the distribution of ARVs can be improved so that patients can receive an uninterrupted supply. The nature of the topic researched dictated the use of mainly the quantitative research method.The main problems identified include: Wrong and no uniform practice of ordering stock by the hospital and the clinics; lack of reliable, structured transportation from the depot to the hospital; as well as poor inventory management and poor overall communication. Recommendations to address the problems include: Implementing a supply chain planning and design process; improving inventory management and warehousing practices; implementing more effective and reliable distribution and transportation processes; as well as improving supply chain coordination and overall communication.

Role of biomass supply chain management in sustainable bioenergy production

ABSTRACTThe demand for bioenergy (biofuels, heat and electricity) is increasing steadily around the globe. Major policy-related interventions for adoption and promotion of bioenergy have also been realized by several countries over the past few decades. The biomass supply chain incorporates several components of bioenergy production, which in turn consist of several activities for which different alternative methods are available. Different components of the biomass supply chain include production of bioenergy feedstock (biomass), logistics of biomass, conversion of biomass to bioenergy, and distribution of bioenergy or bioenergy carriers for end use. The single largest limiting factor for the production of bioenergy is the unavailability of biomass. Dedicated, fast-growing and high-biomass-producing plantations on non-arable land and utilization of agro-industrial waste materials can overcome this problem. Holistic integration of different components of the biomass supply chain and activities involved therein along with judicious design are likely to enhance the quantum of energy return, improve the greenhouse gas balance and reduce the water footprint of the bioenergy production facility. Additionally, the emerging yet promising concept of lignocellulosic and algal biorefinery would require a careful and prudent design of the biomass supply chain to achieve one of the most attractive characteristic of bioenergy: environmental sustainability.

Reconfigurable radio receiver with fractional sample rate converter and multi-rate ADC based on LO-derived sampling clock

ABSTRACTA composite radio receiver back-end and digital front-end, made up of a delta-sigma analogue-to-digital converter (ADC) with a high-speed low-noise sampling clock generator, and a fractional sample rate converter (FSRC), is proposed and designed for a multi-mode reconfigurable radio. The proposed radio receiver architecture contributes to saving the chip area and thus lowering the design cost. To enable inter-radio access technology handover and ultimately software-defined radio reception, a reconfigurable radio receiver consisting of a multi-rate ADC with its sampling clock derived from a local oscillator, followed by a rate-adjustable FSRC for decimation, is designed. Clock phase noise and timing jitter are examined to support the effectiveness of the proposed radio receiver. A FSRC is modelled and simulated with a cubic polynomial interpolator based on Lagrange method, and its spectral-domain view is examined in order to verify its effect on aliasing, nonlinearity and signal-to-noise ratio, giving insight into the design of the decimation chain. The sampling clock path and the radio receiver back-end data path are designed in a 90-nm CMOS process technology with 1.2V supply.

THE STUDY OF DYNAMIC PROCESSES DURING THE TRANSPORTATION BY CHAIN CONVEYOR

Work of chain conveyor is characterized by considerable dynamic loads in its elements. Although dynamic processes in conveyor traction elements studied in many works, the problem of analysis of stress-strained state of conveyors is covered not enough. Therefore, modeling and optimization of transporters transient dynamic processes as multimass systems are of great practical importance because they determine the performance and reliability. Methods of complex study of the conveyor is to create three-dimensional models, conduct engineering design, dynamic analysis and study of stress-strain state of the most loaded elements. To study and research of stress-strain state software modules can be used for preparation and subsequent finite-element analysis of three-dimensional solid model. Calculation and rational designing concrete poles conveyors includes an assessment of the sections strength for the bearing capacity of the system in which the loss of strength is inadmissible. The equation of the system performing rotational movements, as well as horizontal and vertical movement are composed using the Lagrange equations of the second type. Recommendations to reduce the negative impact of dynamic phenomena affecting on chain conveyor work are proposed, namely dynamic forced oscillations can be reduced by reducing of the chain step, by increasing of chain speed, by offering such chain design that will reduce the negative impact of fluctuations in the dynamic processes of the conveyor.

Multi-objective green supply chain network optimization

In supply chain management, economical objectives have traditionally guided decisions of the supply chains. However, with increased global environmental and social concerns, in recent years, green aspects have been incorporated in supply chain decisions. These expansions lead to new research areas about green or sustainable supply chain management that includes applying various green practices in order to reduce negative impact on the environment or providing sustainable development. The purpose of this study is to develop a multi-objective optimization model for determining network design of the green supply chains. In multi-objective frame of the proposed model, total profit maximization and environmental impact minimization objectives are considered in order to obtain best network configuration for economic and environmental performance of the green chain. The proposed model is validated with numerical experiments. Obtained results showed that the model can be used as a strategic decision tool in problems with multi and conflicting objectives. Keywords: Green supply chain management, multi-objective modelling, network optimization;

Service area size assessment for evaluating the spatial scale of solid waste recovery chains: A territorial perspective

Waste recovery is an integrated part of municipal solid waste management systems but its strategic planning is still challenging. In particular, the service area size of facilities is a sensitive issue since its calculation depends on various factors related to treatment technologies (output products) and territorial features (sources waste production and location). This work presents a systemic approach for the estimation of a chain's service area size, based on a balance between costs and recovery profits. The model assigns a recovery performance value to each source, which can be positive, neutral or negative. If it is positive, the source should be included in the facility's service area. Applied to the case of Montreal for food waste recovery by anaerobic digestion, the approach showed that at most 23 out of the 30 districts should be included in the service area, depending on the indicator, which represents around 127,000 t of waste recovered/year. Due to the systemic approach, these districts were not necessarily the closest to the facility. Moreover, for the Montreal case, changing the facility's location did not have a great influence on the optimal service area size, showing that the distance to the facility was not a decisive factor at this scale. However, replacing anaerobic digestion by a composting plant reduced the break-even transport distances and, thus, the number of sources worth collecting (around 68,500 t/year). In this way, the methodology, applied to different management strategies, gave a sense of the spatial dynamics involved in the recovery chain's design. The map of optimal supply obtained could be used to further analyse the feasibility of multi-site and/or multi-technology systems for the territory considered.

Supply chain network design under uncertain demand: robust and stable optimisation approaches

This paper is focused on the design of a supply chain taking into account the variability of the final customer demand: the traditional strategy for the network configurations so as to face such uncertainty, named robust approach, to seek the minimum expected total cost over the planning horizon. The novelty of this contribution resides in the investigation of an alternative way to face the uncertainty, named stable approach, which aim is to determine the minimum variability of transport and handling cost in the considered time horizon. The goal is the definition of the network configuration that can efficiently operate under the uncertainty of the customer demand, to this extent the solutions of the robust and the stable approaches have been compared. A numerical analysis has been performed over a realistic case study data and results of robust and stable and hybrid solutions have been reported.

New Strategy to Optimize Lean Supply Chain Design by Meta-Heuristic

This paper aims at presenting one novel quantitative strategy of optimizing the design of Lean supply chain using Meta-Heuristics. While classifying Lean Manufacturing tools in two categories, namely Functional and Tier Lean tools, we propose a new framework to design the Lean supply chain by implementing the former into a 5-echelon Fat supply chain. As the following step, we investigate the effect of the latter on the mentioned Lean supply chain model. Then, we utilize the tight correlation of Tier Lean tools and priority-based Genetic Algorithm Meta-Heuristics in order to optimize the configuration of the Lean supply chain. Finally, these ideas are illustrated step by step in one numeral example.

Developing an evaluation methodology for determining the provision energy effort of primary resources using energy value stream mapping

Abstract The immense growth in complexity regarding the planning and design of primary and secondary resource chains has a negative effect on the process efficiency in the production industry due to a lack of process transparency. Analyzing the energy consumption of primary resources used along the entire supply chain from resource retrieval until their deployment in final products has so far not been at the center of these considerations. The following contribution addresses these problems and offers a possible solution for increasing process transparency and increasing resource efficiency.

Redesigning the Hospital Supply Chain for Enhanced Performance Using a Lean Methodology

The supply chain of medicines is a fundamental component of the health care system. It requires a good management in order to enhance hospital performance. This paper describes a model of designing the distribution network of health products within hospitals. Different scenarios are studied using multi-criteria analysis in order to identify the most appropriate design of the hospital supply chain in terms of costs reduction, accessibility and quality of care improvement. The purpose is to define the most performing supply chain design based on three criteria: costs, accessibility and quality. The adopted design/methodology/approach is based on the analytic hierarchy process (AHP): a structured technique that assists decision makers to choose the best solution in complex situations taking on account multiple decision criteria. This paper proposes to compare six organizational scenarios of the hospital distribution network and in the end, to choose the most appropriate one based on three criteria: quality of services, accessibility and costs. Based on the AHP method, among the healthcare supply chain designs reviewed in the case study, the highest performance for pharmacies grouping is obtained by reducing costs and increasing the health products availability and quality. This grouping doesn’t concern all the medicines and medical devices but only a part of them. The three organizational scenarios that represent the grouping of all health products (the second, the fourth and the fifth) occupy the last three ranks. The actual situation occupies the third rank. That is to say, that the reorganization of the hospital distribution network is required to improve the hospital performance. The originality lies on the use of the AHP (Analytic Hierarchy Process) method to choose the most appropriate design of healthcare supply chain in a case study based on three decision criteria: costs, accessibility to health products and quality. The originality of the model is the assessment of performance in the light of the presumed perception of all actors of hospital (patients, medical staff and managers).

Tuning the Sawtooth Tensile Response and Toughness of Multiblock Copolymer Diamond Networks

Liquid crystalline elastomers of block copolymer chains end-linked into a diamond network have recently been shown to exhibit a sawtooth tensile response to uniaxial deformation [Macromolecules 2014, 47, 840−850], which can provide the basis to design supertough, highly stretchable materials. Molecular dynamics is used to study different chain designs that modulate the number of “teeth” and the strain-orientation dependence of the previously reported tensile response of ABA (25%–50%–25%) chains. Two chain designs with distinct tensile behaviors have been identified. First, ABA (15%–70%–15%) chains with lower backbone stiffness are found to exhibit a stress response independent of the extensional direction by virtue of morphological rearrangements occurring at low strains. Second, ABACA (20%–20%–20%–20%–20%) pentablock chains are found to exhibit a sawtooth response with twice as many “teeth” for a given strain and hence larger toughness. This architecture allows for more gradual chain unfolding events and...

Design and Management of Sustainable and Resilient Supply Chains

Design and Management of Sustainable and Resilient Supply Chains

Design and Management of Sustainable and Resilient Supply Chains

Design and Management of Sustainable and Resilient Supply Chains

Penentuan Prioritas Risiko pada Rancangan Rantai Pasok Biodiesel dari Minyak Goreng Bekas di Kota Padang

<p><em>A design of biodiesel supply chain from </em><em>waste</em><em> cooking oil conducted in previous studies. Implementation of supply chain design needs to be studied more in</em><em> </em><em>depth and comprehensive. One aspect of the study is a supply chain risk management. Supply chain risk </em><em>management</em><em> is important because many events in supply chain which raises operational problems and the cessation of business activity. Because of vulnerability of the supply chain to various internal and external risks, the study of risk sources is needed. This study examines the sources of risk and the weighting that may occur along the supply chain for the distribution of biodiesel </em><em>from waste</em><em> cooking oil from suppliers</em><em> that</em><em> located in various places until the sale of biodiesel to consumers that are targeted to the public</em><em> in</em><em> Padang.</em><em> The method used in this research is fuzzy AHP with triangular fuzzy number approach. Risk identification is done with the study of literature and assessment by experts. Based on the results obtained sequences risks from largest to smallest weight are raw materials, market, quality, production, transportation, and partnerships.</em></p>

Logistical Support of Interstate Trade and Economic Cooperation

Background: Globalization processes led to the development of international economic integration in the world economy, where logistical issues of trade and economic cooperation have gained particular scientific significance in the last ten years. Methods: In the study the data showing the current state of the world trade were analyzed, as well as the features of regional logistical capabilities and tendencies of trade policy of the Eurasian Economic Union (EEU) were discussed. In order to rationally use geo-economic resources of integrated formation, the need to create a common logistical space, including regional logistical centers, objects of near-customs, transport and other infrastructures, logistical informational systems, etc., was defined by general scientific and special methods of structural-functional analysis and organizational design. Findings: The article focuses on the key objectives of unification of the countries into international trade and economic blocs: The total economic and social development, provision of favorable conditions for the development of bilateral trade and strengthening of competitive geopolitical advantages. According to the author’s opinion, the regional economic integration allows member countries to use economic, logistic and natural-resource potential of the macroregion according to the principles of synergy. Due to the fact that the international cooperation involves the creation of a common customs and economic space, where the free movement of goods, labor and capital takes place – the formation of a common logistical space is becoming an integral part of regional trade and economic system, ensuring the needs of international business structures. The uniqueness of the author’s proposals relates to strengthening of the integration processes in the regional cross-border area, where one of the most urgent tasks is to create an efficient infrastructure base for the organization of export-import and transit goods movement. In this article the author reviews the prerequisites for the formation of the Eurasian Economic Union (EEU), special aspects of integration processes development in the post- Soviet space, the key trends of EEU trade policy and the specificity of EEU logistical potential implementation in terms of resource constraints. Application/Improvements: The obtained research results can be applied in the framework of trade policy of regional integrated union, as well as be taken into account in the design of global supply chains of business entities.

Hub and Chain: Process Flexibility Design in Non-Identical Systems Using Variance Information

In multi-product multi-plant manufacturing systems, process flexibility is the ability to produce different types of products in the same manufacturing plant or production line. While several design methods and flexibility indices have been proposed in the literature on how to design process flexibility, most of the insights generated are focused on identical production systems whereby all plants have the same capacity and all products have identically distributed demands. In this paper, we examine the process flexibility design problem for non-identical systems. We first study the effect of non-identical demand distributions on the performance of the well-known long chain design, and discover three interesting insights: (1) products with low demand mean will create a bottleneck effect, (2) products with low demand variance will result in inefficient utilization of flexibility links, and (3) long chain efficiency decreases in demand variance of any product, hence the need to provide this product with access to more capacity. Using these insights, we develop the variance-based hub-and-chain method (VHC), a simple and graphically intuitive method which decomposes the long chain into smaller chains, one of which will serve as a hub to which the other chains will be connected. Numerical tests show that VHC outperforms the long chain by 15% on average and outperforms the constraint sampling method by 38% on average. Lastly, we implement VHC on a case study in the edible oil industry in China and find substantial benefits. We then summarize with some managerial insights.

Special issue on design and management of sustainable and resilient supply chains

Special issue on design and management of sustainable and resilient supply chains

Online Resource Allocation with Limited Flexibility

We consider a class of online resource allocation problems in which there are n types of resources with limited initial inventory and n demand classes. The resources are flexible in that each type of resources can serve more than one demand class. In this paper, we focus on a special class of structures with limited flexibility, the long chain design, which was proposed by Jordan and Graves (1995) and has been an important concept in the design of sparse flexible processes. We study the long chain design in an online stochastic environment where the requests are drawn repeatedly and independently from a known probability distribution over the different demand classes. Also, the decision on how to address each request must be made immediately upon its arrival. We show the effectiveness of the long chain design in mitigating supply-demand mismatch under a simple myopic online allocation policy. In particular, we provide an upper bound on the expected total number of lost sales that is irrespective of how large the market size is.