Search results for "Envelopment"
showing 10 items of 125 documents
DEA-like Models for the Efficiency Evaluation of Hierarchically Structured Units
2004
Abstract The knowledge of the internal structure of decision making units (DMUs) gives further insights with respect to the “black box” perspective when considering data envelopment analysis models. We present one-level and two-level hierarchical structures of the DMUs under evaluation. Each unit is composed of consecutive stages of parallel subunits all with constant returns to scale. In particular, the maximization of the relative efficiency of a DMU is studied. For the two-stage situation, different degrees of coordination among the subunits of the hierarchical levels are discussed. When some form of coordination has to be guaranteed, we introduce balancing constraints and we compare two…
A fuzzy mathematical programming approach to the assessment of efficiency with DEA models
2003
In many real applications, the data of production processes cannot be precisely measured. This is particularly worrying when assessing efficiency with frontier-type models, such as data envelopment analysis (DEA) models, since they are very sensitive to possible data errors. For this reason, the possibility of having available a methodology that allows the analyst to deal with imprecise data becomes an issue of great interest in these contexts. To that end, we develop some fuzzy versions of the classical DEA models (in particular, the BCC model) by using some ranking methods based on the comparison of α-cuts. The resulting auxiliary crisp problems can be solved by the usual DEA software. We…
Classifying efficient alternatives in SMAA using cross confidence factors
2006
Abstract Stochastic multicriteria acceptability analysis (SMAA) is a family of methods for aiding multicriteria group decision making. These methods are based on exploring the weight space in order to describe the preferences that make each alternative the most preferred one. The main results of the analysis are rank acceptability indices, central weight vectors and confidence factors for different alternatives. The rank acceptability indices describe the variety of different preferences resulting in a certain rank for an alternative; the central weight vectors represent the typical preferences favouring each alternative; and the confidence factors measure whether the criteria data are suff…
A DEA-based transport heliports' efficiencies evaluation
2015
Purpose - The purpose of the study is the evaluation of the efficiencies of a group of small Italian airports and the comparison with a set of transport heliports to show the difference in the productivity of the two types of infrastructures. Design/methodology/approach - The methodology used for the evaluation is the data envelopment analysis (DEA). Findings - The better performance of the heliports compared to the small inefficient airports. Research limitations/implications - This research is limited by the field of application and the weaknesses of the DEA methodology. However, it could be the first step for further works that will include more accurate models. Practical implications - …
Multiple-attribute decision support system based on fuzzy logic for performance assessment
2005
Abstract This paper deals with the problem of assessing the performance of a set of production units, simultaneously considering different kinds of information, yielded by a Data Envelopment Analysis, a qualitative data analysis and an expert assessment. The tool for integrating heterogeneous data is a model that applies fuzzy logic to decision support systems. The results obtained are a holistic performance assessment of each unit of the set and a ranking order of the units.
Performance and convergence in municipal waste treatment in the European Union.
2019
This paper assesses performance and convergence in the treatment of municipal waste by the members of the European Union-27 (EU-27) during the period 1995-2016. First, a composite indicator of performance -including landfill, incineration, recycling, and composting and digestion as treatment operations- is computed with Data Envelopment Analysis and Multi-Criteria-Decision-Making techniques at country and year levels. Then, convergence is assessed using the techniques proposed by Phillips and Sul (2007, 2009) and, more recently, by Kong et al. (2017). The best performers are Central and Northern European countries such as Denmark, Austria and Germany, whereas the worst are some Eastern Euro…
Monitoring managerial efficiency in the performing arts: A regional theatres network perspective
2006
Managerial efficiency within the performing arts programming can be understood as the technical efficiency of transforming the resources cultural managers have available into a determined cultural output. Through this explanation different conceptions on the finished performance product it leads us to select two different output variables (number of performances, and number of attendances). In this way, three different models are considered regarding those conceptual points of view. Data on the Circu¨ıt Teatral Valencia`, a Spanish regional theatres network, is used to develop empirically the concept of Managerial Efficiency and set up a framework to allow us to monitor it. Publicaciones Ec…
On the importance of perspective and flexibility for efficiency measurement: effects on the ranking of decision-making units
2017
[EN] The efficiency of a firm can be assessed from several perspectives and using a variety of methodologies. Data envelopment analysis (DEA) is one of the most commonly used methodologies. Conventional DEA analyses or models allow one to classify decision-making units (DMUs) into efficient and inefficient ones based on their efficiency scores, which could also be used for ranking DMUs; however, such rankings generally show many ties. Super-efficiency DEA analyses have been proposed to address the tie issue. On the other hand, conventional DEA analyses only take account of a single perspective in estimating efficiency scores. Cross-efficiency DEA analyses provide an alternative that takes a…
Congestion analysis to evaluate the efficiency and appropriateness of hospitals in Sicily
2015
Over the past twenty years, important changes in the Italian National Health System have been made in order to obtain significant improvements in the efficiency, appropriateness and quality of health care delivery, while reducing health expenditure. In this paper we proposed a multidimensional approach to assess the impact of organization inappropriateness on the efficiency evaluation of hospitals in Sicily for the year 2009. This study was based on cross-sectional data for 116 (out of 129) short-term, acute-care hospitals. The analysis considered beds, physicians, nurses and other personnel as inputs, ordinary discharges and day-hospital admissions as desirable outputs and inappropriate di…
A review of DEA models when the internal structure of the decision making units is considered
2005
Classical Data Envelopment Analysis (DEA) models consider each Decision Making Unit (DMU), whose relative efficiency they evaluate, as a "black box", i.e., its internal structure is disregarded. The paper presents a comprehensive framework of the most advanced theoretical findings in DEA when the internal structure of the. DMUs is taken into account, thus giving directions for novel applications of such methodology and introducing it as a powerful toot for complex processes performance evaluation.