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

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

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

A Study on Directional Returns to Scale

This study investigates the directional return to scale of biological institutions in the China Science Academy. In the first stage, the input-output indicators provided including staff, budget of studies, SCI articles, high quality articles and graduate education, etc. In the second stage, the method proposed by Yang (2012) was used to analyse directional return to scale and directional congestion effects on biological institutes in the China Science Academy was studies. The results indicated that diagnosis directional return to scale (incremental, constant, and decreasing)  taken for each biological institute that this information can be the basis for decisions regarding the modification of any organization. Also, congestion and directional congestion occur in several biological institutes. In such cases, when the inputs are increased the outputs of these institutions are reduced. These institutions should analyze the occurrence of congestion of specific cause up to more resources to be used more effectively and useful

PORT PERFORMANCE AND CRUDE OIL EXPORT LOGISTICS SYSTEM DISTRIBUTION IN NIGERIA

Port Performance and Crude Oil Export Logistics System Distribution in Nigeria. Crude oil export is a resource that provides essential building blocks for economic development and prosperity for Crude oil exporting countries (COECs). Previous research found information flow been significant for logistics and supply chains sustainability. In the current low price environment, key COECs experienced recession, especially brought by the 2014 oil price crash. Obviously, performance of export terminals is vital to maintain competitive advantage. Nigeria’s reputation in the global oil market suffers due to avoidable delay arising because cargoes for tankers are occasionally disrupted through shutdown due to pipeline leaks or sabotage. In addition, when prices are relatively high an evolving energy transition scenario reveals a global shift in demand away from traditional fossil fuel to gas, and increasingly, reducing global demand for fossil fuels. The study was guided by a pragmatic philosophy, commencing with scoping interviews and mixed methods that embraced different analytical techniques. First, a model of key strategies to model port performance. Supply chain management (SCM) concepts were not fully understood by low-cost producers’ and the Nigerian National Petroleum Corporation (NNPC). International oil companies (IOCs operate more effectively than Indigenous companies and NNPC needs to review its business model. Analytical Hierarchy Process (AHP) group decision makers scored the information sharing and synergy between supply chain actors’ strategy to be highest at 22.85%. Investment and security are topical in Nigeria because of inadequate investment in the pipeline automation security system, dredging, security platform and capability, metering systems and information communication technology. Improved port security encompass anti-piracy laws, private maritime security companies. The Petroleum Industry Bill (PIB) remains a key concern for all stakeholders, particularly concerning investment and information sharing networks. Policy contribution includes the use of reliable and accurate metering systems for bill of lading figure. Theoretical contribution revealed template analysis being a rare technique. In addition, weather friendliness has been found to be effective for seamless logistics operations as a resource base view strategy for Nigeria.PETROLEUM TECHNOLOGY DEVELOPMENT FUND (PTDF), NIGERI

Weak congestion in output additive data envelopment analysis

Our earlier work [Wei QL, Yan H. Congestion and returns to scale in data envelopment analysis. European Journal of Operational Research 2004;153:641-60] discussed necessary and sufficient conditions for the existence of congestion together with aspects of returns to scale under an output-oriented DEA framework. In line with this work, the current paper investigates the issue of "weak congestion", wherein congestion occurs when the reduction of selected inputs causes some, rather than all, outputs to increase, without a worsening of others. We define output efficiency for decision making units under a series of typical DEA output additive models. Based on this definition, we offer necessary and sufficient conditions for the existence of weak congestion. Numerical examples are provided for purposes of illustration.Data envelopment analysis Congestion Efficiency