45 research outputs found

    Una investigación de la congestión de productos no deseados en el análisis de envolvente de datos

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    La congestión es uno de los temas más importantes en el análisis envolvente de datos (DEA) que ayuda al responsable de la toma de decisiones (DM) a decidir sobre el cambio de tamaño de las unidades. La estimación de la congestión tiene atractivas ventajas desde diferentes perspectivas. Por ejemplo, el costo total de una DMU en particular, en la que ocurre la congestión, puede reducirse mediante la disminución de los insumos. Por otro lado, la producción de unidades se puede incrementar reconociendo y eliminando la congestión de las DMU y así, se puede incrementar el beneficio total de las unidades de toma de decisiones. Por lo tanto, la gerencia está ansiosa por saber cómo reconocer y eliminar la congestión de unidades. La mayoría de los métodos existentes para estimar la congestión en la literatura consideran solo los resultados deseables. Este estudio se centra en la evaluación de la congestión en presencia de salidas indeseables y propone un enfoque para reconocer la congestión de unidades. El método se demuestra en un ejemplo numérico para ilustrar la validez del método propuesto

    Una investigación de la congestión de productos no deseados en el análisis de envolvente de datos

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    Congestion is one of the most important subjects in Data Envelopment Analysis (DEA) which helps the Decision Maker (DM) to decide about changing the size of units. The estimation of congestion has attractive advantages from different perspectives. For example, the total cost of a partiular DMU, in which the congestion occurs, can be reduced by the decreases in inputs. On the other hand, the output of units can be increased by the recognizing and eliminating the congestion of DMUs and so, the total profit of decision making units can be increased. Hence, the management is eager to know how to recognize and eliminate the congestion of units. Most of the existing methods to estimation of the congestion in the literature consider only the desirable outputs. This study focuses on the evaluation of congestion in the presence of undesirable outputs and proposes an approach to recognize the congestion of units. The method is demonstrated on a numerical example to illustrate the validity of the proposed method.La congestión es uno de los temas más importantes en el análisis envolvente de datos (DEA) que ayuda al responsable de la toma de decisiones (DM) a decidir sobre el cambio de tamaño de las unidades. La estimación de la congestión tiene atractivas ventajas desde diferentes perspectivas. Por ejemplo, el costo total de una DMU en particular, en la que ocurre la congestión, puede reducirse mediante la disminución de los insumos. Por otro lado, la producción de unidades se puede incrementar reconociendo y eliminando la congestión de las DMU y así, se puede incrementar el beneficio total de las unidades de toma de decisiones. Por lo tanto, la gerencia está ansiosa por saber cómo reconocer y eliminar la congestión de unidades. La mayoría de los métodos existentes para estimar la congestión en la literatura consideran solo los resultados deseables. Este estudio se centra en la evaluación de la congestión en presencia de salidas indeseables y propone un enfoque para reconocer la congestión de unidades. El método se demuestra en un ejemplo numérico para ilustrar la validez del método propuesto

    Novel approaches to performance evaluation and benchmarking for energy-efficient multicast: empirical study of coded packet wireless networks

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    With the advancement of communication networks, a great number of multicast applications such as multimedia, video and audio communications have emerged. As a result, energy efficient multicast in wireless networks is becoming increasingly important in the field of Information and Communications Technology (ICT). According to the study by Gartner and Environmental Protection Agency (EPA) report presented to United State Congress in 2007,energy consumption of ICT nodes accounts for 3% of the worldwide energy supply and is responsible for 2% of the global Carbon dioxide (CO2) emission. However, several initiatives are being put in place to reduce the energy consumption of the ICT sector in general. A review of related literature reveals that existing approaches to energy efficient multicast are largely evaluated using a single metric and while the single metric is appropriate for effective performance, it is unsuitable for measuring efficiency adequately. This thesis studied existing coded packet methods for energy efficiency in ad hoc wireless networks and investigates efficiency frontier, which is the expected minimum energy within the minimum energy multicast framework. The energy efficiency performance was based on effective evaluation and there was no way an inefficient network could reach a level of being an efficiency frontier. Hence, this work looked at the position of how true efficiency evaluation is obtained when the entire network under examination attains their efficiency frontiers using ratios of weighted outputs to weighted inputs with multiple variables. To address these challenges and assist network operators when formulating their network policies and performing network administrations, this thesis proposed novel approaches that are based on Data Envelopment Analysis (DEA) methodology to appropriately evaluate the efficiency of multicast energy and further minimizes energy transmission in ad hoc wireless networks without affecting the overall network performance. The DEA, which was used to study the relative efficiency and productivity of systems in Economic and Operational Research disciplines, is a non-parametric method that relies on linear programming technique for optimization of discrete units of observation called the decision making units (DMUs)

    The governance-production nexus of eco-efficiency in Chinese resource-based cities:A two-stage network DEA approach

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    For decades, resource-based cities in China have significantly contributed to China's socio-economic development. The heavy resource dependence of resource-based cities inevitably leads to a series of environmental problems. Mitigating environmental impacts in an unthinking manner might be disruptive for economic development. Improving eco-efficiency has been a crucial solution for protecting the environment while mitigating its negative economic impact. However, the method commonly used to evaluate the eco-efficiency – that is, the black-box data envelopment analysis (DEA) – cannot examine the inefficiencies of the internal structure, and as a result, the underlying management defects are unclear. To open the black box, this study presents a two-stage network DEA framework incorporating government and industrial sectors and measures the eco-efficiency of 84 resource-based cities during the post-financial crisis period (2007–2015). The results indicate that the average eco-efficiency of China's resource-based cities shows a promising increase, and there is a positive relationship between governance efficiency and production efficiency. The decreasing trend of governance efficiency in the Central, Western, and Northeast regions after 2014 shows the low quality of the government sector in the usage of fiscal income. Proactive disclosure of how the government sector conducts public business and spends taxpayers' money should be made to increase transparency, attract more entrepreneurial resources to carry out production activities, and further improve sustainability. The two-stage network DEA framework helps obtain more insights into the internal management defects of the government and industrial sectors and enhance their cooperation to improve the eco-efficiency precisely

    Bootstrapping in Network Data Envelopment Analysis

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    Data Envelopment Analysis (DEA) is a linear-programming method used to measure the relative efficiency of firms. The objective of this thesis is (i) to study the efficiency of the railway transport process in Europe considering its inner structure and the impact of railway noise on humans and (ii) to study the performance of bootstrapping approaches in obtaining DEA efficiency estimates when the production process has a network structure and the relation between the different stages is considered. First, the railway transport process is divided into two stages, related to assets and service provision, respectively. The negative impact of railways on people is measured as the number of people that are exposed to high levels of railway noise. The number of rail wagons in each country that is retrofitted with more silent braking technology is used as a proxy to measure the effort to reduce railway noise pollution. Data is extracted from Eurostat (2016), ERA 006REC1072 Impact Assessment (2018), and EEA (2020) and the additive efficiency decomposition approach is used. Based on the results, asset-efficient countries are usually service-efficient, but the inverse does not hold. Sensitivity analysis revealed that efficiency rankings are robust to alterations in the decomposition weight restrictions. Subsampling bootstrap was chosen as the most appropriate as it does not require any restrictive assumptions. The performance of subsampling is examined through Monte Carlo simulations for various sample and subsample sizes for general two-stage series structures. Results indicate great sensitivity both to the sample and subsample size, as well as to the data generating process-higher than in one-stage structures. A practical approach is suggested to overcome some result inconsistencies that are due to the peculiarities of the additive decomposition algorithm. The method is applied to obtain confidence interval estimates for the overall and stage efficiency scores of European railways

    Benchmarking the performance of UK electricity distribution network operators: a study of quality, efficiency and productivity using data envelopment analysis

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    The aim of this thesis is twofold. The first is to develop a comprehensive methodology for assessing performance and then to apply it to the UK electricity distribution network operators (DNOs) to analyse the impact of the regulatory reforms and privatisation introduced in 1990-91 on their quality, efficiency and productivity developments. The models and methods developed will not only be useful in the electricity distribution context but also to other organisations that need to assess and monitor both their efficiency and quality. These objectives are realised through the use of the Data Envelopment Analysis (DEA) method, the main subject area of this thesis. This method has recently become very popular in the empirical literature due to the minimal assumptions underlying it, the case of handling multiple inputs and outputs, and its usefulness in the measurement of productivity. Performance measurement needs to keep pace with the changes in the industry. With the developments in energy and regulatory policy, and the enactment of the Utilities Act 2000, the focus of regulation has broadened from a narrow economic focus towards a wider one of protecting the interests of consumers. The latter includes not only price but also quality of service. Given this broadening focus, it is essential that performance measurement takes into account these aspects. This thesis incorporates new dimensions into efficiency and productivity measurement of electricity distribution network operators by taking into account the quality characteristics of electricity distribution operations. The dimensions of quality of service in electricity distribution were defined in this study, namely the quality of supply dimension and the quality of customer service dimension. Plausible measures of service quality were suggested. In order to provide a more balanced performance assessment, the new DEA model that incorporates the quantity as well as the quality of the services that distribution network operators provide their customers was used. In this study, only the quality of supply dimension was used in the analysis. (The quality of customer service dimension was omitted due to lack of data). Besides this, in order to achieve a more comprehensive assessment, both the operating and capital costs of distribution operations were included as inputs. The technological realities of the electricity distribution production process were captured in this study by taking into account the production trade-offs that exist between inputs and outputs. When trade-offs occur, the reduction in one factor can lead to increases in another, thereby reducing the overall reduction. The reflection of production trade-offs provides more reliable results than can be utilised in management and policy making. The production trade-offs were accounted by developing an enhanced DEA model using weight restrictions that are constructed on the basis of production trade-offs. The enhanced DEA model thus was referred to as the ‘weight-restricted’ model. This model developed was used to evaluate the DNOs efficiencies in 1999/00. A new productivity index called the ‘weight-restricted’ Malmquist productivity index was also developed in order to evaluate the quality and productivity changes of the DNOs since 1990/91. This new index is similar in spirit to the Malmquist productivity index but it reflects production trade-offs and service quality rather than just quantities per se. In this regard, the index is more appropriate to evaluate the DNOs. The index was decomposed in this study into its root components of efficiency change and technological change

    Benchmarking the performance of UK electricity distribution network operators : a study of quality, efficiency and productivity using data envelopment analysis

    Get PDF
    The aim of this thesis is twofold. The first is to develop a comprehensive methodology for assessing performance and then to apply it to the UK electricity distribution network operators (DNOs) to analyse the impact of the regulatory reforms and privatisation introduced in 1990-91 on their quality, efficiency and productivity developments. The models and methods developed will not only be useful in the electricity distribution context but also to other organisations that need to assess and monitor both their efficiency and quality. These objectives are realised through the use of the Data Envelopment Analysis (DEA) method, the main subject area of this thesis. This method has recently become very popular in the empirical literature due to the minimal assumptions underlying it, the case of handling multiple inputs and outputs, and its usefulness in the measurement of productivity. Performance measurement needs to keep pace with the changes in the industry. With the developments in energy and regulatory policy, and the enactment of the Utilities Act 2000, the focus of regulation has broadened from a narrow economic focus towards a wider one of protecting the interests of consumers. The latter includes not only price but also quality of service. Given this broadening focus, it is essential that performance measurement takes into account these aspects. This thesis incorporates new dimensions into efficiency and productivity measurement of electricity distribution network operators by taking into account the quality characteristics of electricity distribution operations. The dimensions of quality of service in electricity distribution were defined in this study, namely the quality of supply dimension and the quality of customer service dimension. Plausible measures of service quality were suggested. In order to provide a more balanced performance assessment, the new DEA model that incorporates the quantity as well as the quality of the services that distribution network operators provide their customers was used. In this study, only the quality of supply dimension was used in the analysis. (The quality of customer service dimension was omitted due to lack of data). Besides this, in order to achieve a more comprehensive assessment, both the operating and capital costs of distribution operations were included as inputs. The technological realities of the electricity distribution production process were captured in this study by taking into account the production trade-offs that exist between inputs and outputs. When trade-offs occur, the reduction in one factor can lead to increases in another, thereby reducing the overall reduction. The reflection of production trade-offs provides more reliable results than can be utilised in management and policy making. The production trade-offs were accounted by developing an enhanced DEA model using weight restrictions that are constructed on the basis of production trade-offs. The enhanced DEA model thus was referred to as the ‘weight-restricted’ model. This model developed was used to evaluate the DNOs efficiencies in 1999/00. A new productivity index called the ‘weight-restricted’ Malmquist productivity index was also developed in order to evaluate the quality and productivity changes of the DNOs since 1990/91. This new index is similar in spirit to the Malmquist productivity index but it reflects production trade-offs and service quality rather than just quantities per se. In this regard, the index is more appropriate to evaluate the DNOs. The index was decomposed in this study into its root components of efficiency change and technological change.EThOS - Electronic Theses Online ServiceAssociation of Commonwealth Universities (ACU)GBUnited Kingdo

    Data envelopment analysis with production trade-offs : the case of microfinance institutions

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    The success of microfinancing methodology, as a development tool for poverty alleviation, has been accompanied by a number of challenges. These challenges have resulted in increasing concerns about performance of those entities that act as vehicles for delivering microfinance, i.e. the microfinance institutions (MFIs). A major problem in this regard relates to selection of appropriate technique/s for evaluating MFIs’ performance. Data Envelopment Analysis (DEA) is an established nonparametric methodology that has been used to assess the performance of MFIs. This study proposes a significant extension to standard DEA models. This is achieved by the identification of various trade-offs between the inputs and outputs and their subsequent incorporation in the DEA models. With this application, the current study contributes to existing knowledge in the field of operational research; by providing practical demonstration of the procedure, through which the trade-off approach can be used to enrich standard DEA models. The improvement to standard DEA models is accomplished through incorporation of additional information, in the form of technologically realistic trade offs. In addition, application of the trade-off approach is shown to help in overcoming the problem of insufficient discrimination; resulting from having a relatively small number of DMUS, in comparison to the total number of input and output variables. The current study also proposes a framework for DEA-based performance evaluation of MFIs. This framework acknowledges the need to evaluate both the social and financial dimensions of MFIs, in order to achieve a more holistic view of their performance. For this purpose, the social and financial performance aspects of a group of MFIs’, working in an under-researched economy, are analysed individually as well as simultaneously. A comparison of the efficiency scores is also used for investigating the conflict compatibility dilemma, which is a frequently discussed issue in the microfinance literature

    Studies on Some Aspects of Service Quality Evaluation with Specific Relevance to Indian Service Industries

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    Quality has been treated as a major competing weapon by both the manufacturing industries and service providers to gain market share, improve productivity and profitability and sustain in business from long term perspective. Therefore, organizations throughout the world dealing with products or services or both are contemplating to implement Total Quality Management (TQM) principles for enhancing system effectiveness. Literature on TQM suggests that twenty critical factors ease the process of TQM implementation in any organization. However, few critical factors viz., leadership, customer satisfaction, training, and employee’s participation are emphasized more frequently in the literature compared to other factors. It is also observed that standardization of the best set of principles of TQM and their implementation sequence is difficult because diverse set of TQM principles are being adopted by organizations. Exhaustive investigation on implementation aspects of TQM results in an in..
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