This paper develops a method based on data envelopment analysis (DEA) for efficiency assessments taking into account the effect of non-discretionary factors. A typology that classifies the non-discretionary factors into two groups is proposed: the factors that characterize the external conditions where the decision making units (DMUs) operate (external factors), and the factors that are internal to the production process but cannot be controlled by the decision makers (internal factors). This paper proposes an enhanced DEA model that accommodates non-discretionary inputs and outputs and treats them differently depending on their classification as internal or external to the production process. This generalized model integrates the previous approaches for dealing with non-discretionary variables described in the DEA literature. The model defines the efficient frontier based exclusively on the discretionary variables and internal non-discretionary factors, but the potential peers of each DMU are restricted to other units facing comparable external conditions (represented by the external nondiscretionary factors). The peer selection criteria implemented in the DEA model is informed by decision makers' opinion. The applicability of the model developed is illustrated with a real-world assessment of retailing stores.

EURO 24 -Lisbon 2010Traveling salesperson problem (TSP) instances encountered in real-world logistics operations are often sparse and asymmetric, and of large size. The literature on tabu search heuristics for the traveling salesman problem primarily deals with relatively small symmetric TSPs defined on complete graphs. In this paper, we provide data structures which speed up the performance of tabu search on large sparse asymmetric TSPs. We show that the speed up using our data strucures is significant, and allows us to use tabu search on much larger instances than those reported in the literature. -A new greedy approach to the Quadratic Assignment Problem (QAP)Theodoros Gevezes, Mathematical and Physical Sciences, Aristotle University of Thessaloniki, 51124, Thessaloniki, Greece, theogev@gen.auth.grA new greedy approach is presented for the QAP, where instead of building a solution starting from an empty set, a feasible solution is reached gradually by deleting the worst elements. In order to implement this greedy approach, a set of necessary and sufficient conditions for a zero-one matrix to be a solution of the QAP is proved, while the verification of these conditions requires the solution of linear assignment problem with additional constraints. The new greedy approach has been incorporated in a Greedy Randomized Adaptive Search Procedure (GRASP) with favorable computational results. -A new heuristic for the minimization of tool switches problemEdson Senne, Mathematics, UNESP/FEG, Caixa Postal 205, 12516-410, Guaratingueta, SP, Brazil, elfsenne@feg.unesp.br, Antonio Chaves, Horacio YanasseThe minimization of tool switches problem (MTSP) seeks a sequence to process a set of jobs so that the number of tool switches required is minimized. This work presents a new heuristic for the MTSP. This heuristic has a constructive phase, which is based on a graph where the vertices correspond the tools and exists an arc k=(i,j) binding vertices i and j if tools i and j are necessary for the execution of task k, and an improved phase based on the Iterated Local Search. Computational results show that the proposed heuristic has better performance than other methods from the literature. UMTS is the Third Generation mobile telecoms networks which will bring video, music and internet services to the cell phone and a range of electronic products. This paper deals with the implementation of the UMTS services in the existing GSM900 bandwidth. It focuses on the issue of spectrum and capacity reduction in UMTS900 deployment area and buffer area, which can be seen as an optimization problem, where the decision variable is the number of transmitters that assure an acceptable QoS of the GSM service. An efficient tabu search method is proposed to solve this problem. The point coverage, sink location, and data routing problems are considered within a unified frame and two integrated mixed-integer linear programming formulations are developed. They are difficult to solve and a hybrid procedure is proposed. The best sensor locations are ...

This study develops a framework that combines different management science methods to provide insights concerning the performance of retailing stores. First, the framework enables to specify appropriate targets for stores of a retail network using data envelopment analysis. This involves comparing stores within homogenous groups, that is, supermarkets and hypermarkets. Second, the framework compares the overall performance of these two groups. This requires the combined use of a Malmquist-type index and statistical tests. This index is decomposed into sub-indices for comparing the differences between groups in terms of the efficiency spread in each group of stores and the productivity differences between the best-practice frontiers spanned by the benchmark stores from each group. The hypothesis tests are used to verify if the differences between groups captured by the sub-indices are statistically significant.

The transport sector plays a fundamental role in the European Union economy and its efficiency is fundamental to strengthen the region's environmental and economic performance. Unfortunately, the sector still remains heavily dependent on oil resources and is responsible for a large part of the air pollution. The European Union has been promoting various initiatives towards sustainable transport development by setting targets in the sector such as the ones proposed in the 2011 White Paper on transport. Under this context, this study aims at evaluating the environmental performance of the transport sector in 28 European Union countries, from 2015 to 2018, towards the policy agenda established in the strategic documents. The assessment of the transport environmental performance is made through the aggregation of seven sub-indicators into a composite indicator using a Data Envelopment Analysis technique. A variant of the Benefit of the Doubt model is used to determine the weights to aggregate the sub-indicators. The results obtained indicate that the European Union countries have been improving their transport environmental performance in the last two years of the time span under analysis, i.e., 2017 and 2018. Regarding the inefficient countries, results suggest they should improve the transport sustainability mainly by drastically reducing the greenhouse gas emissions from fossil fuel-based propulsion, increasing the share of freight transport using rail and inland waterways and also the share of transport energy from renewable sources.

This paper aims to analyse the bi-directional relationship between technical efficiency, as a measure of companies' performance, and capital structure, under the agency cost theory as well as the pecking order and trade-off theory, to explain the capital structure decisions. The technical efficiency was estimated by the DEA method and corrected by using a suitable bootstrap to obtain statistical inferences. To test the agency cost hypothesis, asymmetric information hypothesis, risk-efficiency hypothesis and franchise value hypothesis (under pecking order and trade off theories framework), two models were applied using some determinants of capital structure such as size, profitability, tangibility, liquidity as control and explanatory variables through a truncated regression with bootstrapping. From an initial sample of 1024 small and medium sized companies from the interior of Portugal, for the period 2006-2009, a subsample of 210 SMEs from secondary and tertiary sectors was selected. The results suggest that medium sized companies have higher average bias-corrected efficiency than small companies; that short-term leverage is

Purpose Portugal has been experiencing a continuous growth in tourism activity, with hospitality industry as one of the main tourism sectors. Therefore, the assessment of hotel companies’ performance is very important to assist decision processes. The purpose of this paper is to assess the financial performance (FP) of 570 hotel companies operating hotel units in Portugal in 2017. To explore the question of brand affiliation, a comparison was made between hotel companies with similar stars rating and market orientation. In addition, this paper intends to fill a gap in literature studying the Portuguese reality on the subject of brand affiliation. Design/methodology/approach The present study uses a methodology based on data envelopment analysis (DEA) to assess the overall performance for each company, which further decomposed into the within-group performance and the technological gap. The performance of the hotel company is assessed through the aggregation of multiple financial indicators using the composite indicator (CI) derived from the DEA model. A bivariate analysis based on the Tobit regression to test the robustness of brand effect on FP of hotel companies (HC) was also included. Findings The empirical results show that branded companies, on average, have significantly better overall FP than non-branded companies. On the one hand, the brand effect tends to improve the within-group FP of HCs and the brand presents a statistically significant positive effect on the FP. On the other hand, the best practices are observed in both branded and non-branded companies. Practical implications The results of this study illustrate that, globally, the better FP of the branded companies is because of their individual relative companies’ performance and a better model of operation given by the brand effect. Brand affiliation will generally allow for a better FP and essentially a better profitability for invested equity, a higher return on sales and a higher value added per employee. Originality/value The study provides important theoretical and practical contributions that can assist the strategic decision of the HCs in choosing to operate independently or to adopt brand affiliation. Also, it is innovative because the FP of branded and non-branded HCs is measured not using a set of individual financial ratios but through a single CI that aggregates those financial ratios, using a DEA model.

A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos.Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença.Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso. Measuring technical efficiency of European Countries using data envelopment analysis Autor(es):Vaz, Clara Bento; Ferreira, Ângela Paula

This study aims to evaluate the economic eciency of Nursing Homes owned by 96 Santas Casas da Misericórdia (SCM) and the determinants that inuenced their eciency in 2012 and 2013. The SCM are the oldest non-prot entities, which belong to Third Sector in Portugal, provide this social response and receive signicant nancial contributions annually from the state. The study is developed in two stages. In the rst stage, the eciency scores were calculated through the non-parametric DEA technique. In the second stage, Tobit regression is used to verify the eect of certain organizational variables on eciency, namely the number of users and existence of Nursing Home chains. The results of the DEA model show that the eciency average is 81.9%, and only 10 out of 96 Nursing Homes are ecient. Tobit regression shows that the number of users has a positive eect on the eciency of Nursing Homes, whereas the existence of Nursing Home chains aects their eciency negatively.