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1

Evaluating carbon emission efficiencies in European Union transport: pre and post pandemic analysis

İpekçi Emre, Tanyaş Mehmet, Toygar Arda

LogForum

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2025

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Vol. 21, no 2

287--302

EN

Background: Reducing carbon emissions has become a strategic priority for sustainable logistics and supply chain management in the European Union (EU). The European Green Deal promotes decarbonization initiatives across key sectors, including transportation. This study evaluates the carbon emission efficiency of 25 EU countries across four transport modes-road, rail, air, and sea-before and after the COVID-19 pandemic, offering insights into sustainable transport and logistics performance. Methods: Data Envelopment Analysis (DEA) was applied to assess the efficiency of energy use and employment inputs for each mode of transport mode. Inputs included rail and road lengths, as well as the number of trucks, while outputs comprised emission values, passenger numbers, freight volume, and port cargo throughput for maritime transport. Efficiency scores were calculated using both constant and variable returns-to-scale models to provide a comparative analysis across transport types. Results: The results reveal significant shifts in carbon emission efficiency between the pre- and post-EU pandemic periods. In road transport, three countries maintained efficiency, four lost efficiency, and four improved. Rail transport was relatively stable, with eight countries maintaining their scores but three declining. Air transport remained the least efficient, with only three countries maintaining efficiency post-pandemic. Maritime transport showed limited progress, with two countries consistently efficient and seven improving under select some models. These findings underscore the need for intermodal logistics strategies, investments in low-carbon technologies, and greater integration between modes to enhance EU carbon efficiency. Conclusions: Efficiency outcomes varied before and after the COVID-19 pandemic, indicating opportunities for countries to transform transportation systems to meet sustainability goals. The study provided valuable direction for policymakers and industry stakeholders in shaping post-pandemic strategies aligned with decarbonization goals.

2

Container terminal efficiency under external shocks: A hybrid DEA-Regression analysis of Dar es Salaam port (2019-2023)

Moshi Nasibueli Richard, Meli Benjamin Mbeba

Journal of Sustainable Development of Transport and Logistics

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2025

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Vol. 10, No. 2

107--133

EN

Purpose. This paper evaluates the technical Efficiency of Dar es Salaam Port’s container terminal operations over the period 2019-2023, explicitly accounting for the influence of macroeconomic conditions and the COVID-19 pandemic on performance metrics. The study addresses a critical gap in port efficiency research by disentangling internal operational capability from external contextual factors in a developing-economy maritime gateway serving landlocked East and Central African countries. Methodology. A two-stage hybrid analytical framework integrates input-oriented Data Envelopment Analysis (DEA) with Contextual Value Added (CVA) regression. DEA efficiency scores are computed using a three-year rolling window approach with inputs (quay length, gantry cranes, terminal area) and outputs (container throughput, vessel calls). Second-stage ordinary least squares regression isolates the effects of GDP, trade volume, and pandemic disruption on measured efficiency. Quantitative findings are triangulated with qualitative stakeholder surveys (n=45) and semi-structured interviews to capture operational perceptions and institutional constraints. Results. DEA analysis reveals temporal efficiency variation ranging from 0.838 (2019) to 0.966 (2021), with post-pandemic decline to 0.890 (2023). CVA regression identifies a statistically significant negative relationship between trade volume and efficiency (β = -1.76×10-5, p = 0.03), indicating binding infrastructure constraints. The COVID-19 dummy exhibits a paradoxical positive coefficient (β = +0.090, p = 0.02), reflecting efficiency gains under suppressed demand rather than genuine productivity enhancement. Theoretical contribution. This study advances port efficiency assessment by demonstrating that unadjusted frontier methods can mask capacity deficits when external demand fluctuates. The hybrid DEA-CVA framework enables evidence-based attribution of efficiency sources, enhancing policy relevance. Practical implications. Findings underscore the urgent need for infrastructure expansion and procedural digitalization to accommodate regional trade growth under the African Continental Free Trade Area.

3

Ranking of Efficient Fuzzy Portfolios by Hybrid MSBM-TOPSIS Technique

Aggarwal Abha, Gupta Anjana, Verma Rajkumar, Kumari Reenu

Foundations of Computing and Decision Sciences

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2025

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Vol. 50, No. 1

3--26

EN

This study focuses on ranking of investment portfolios by integrating the Modified Slack Based Measure (MSBM) of Data Envelopment Analysis (DEA) with a multi-criteria decision-making method. Specifically, it extends the MSBM model to evaluate portfolios with positive and negative inputs and outputs in a fuzzy environment using possibilistic mean return of the assets as output and possibilistic variance and semi-variance as inputs. The ranking process involves two stages: first, portfolios are evaluated using an MSBM fuzzy portfolio model, followed by their ranking through the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. This hybrid MSBM-TOPSIS approach provides a robust and reliable ranking system, enabling investors to identify efficient portfolios by leveraging the strengths of both methods. Detailed numerical illustrations are presented here to authenticate the proposed approach and the obtained results are compared with other existing DEA methods that validate the accuracy and feasibility of the proposed technique.

4

Evaluation of the factors determining thermal comfort and occupational health conditions of employees in multi-storey business buildings in the light of expert experiences

Cal Murat, Yilmaz Fatih

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2025

|

Vol. 73, nr 1, Special Section

art. no. e152215

EN

Previous studies generally focused on the indoor temperature of buildings and air supplies to their environment. The effect of outdoor pollutants on thermal conditions has also attracted some interest in recent years. However, the number of studies on other factors that may potentially affect thermal comfort and health in high-rise buildings is limited. A structured analytical hierarchy process and an improved data envelopment analysis method are used in this study to determine the indoor and outdoor spatial features and climatic effects that influence thermal comfort in multi-storey business buildings. The impact levels of these factors on thermal conditions are determined with heuristic algorithms. Further, two climate zones in two countries are compared in terms of the factors that affect thermal comfort and their individual impact levels. The most critical criterion for Kuwait is external insulation features, whereas for Turkey it is indoor air conditioning. The most critical sub-criterion is temperature for Kuwait, whereas for Turkey it is insufficient heat and light insulation of windows. Data envelopment analysis yields that respiratory health diseases are the most critical effect in Kuwait, and work accidents are the most important effect in Turkey. Temperature and humidity play a significant role in thermal comfort in Kuwait. Insulation and air conditioning are crucial factors in thermal comfort conditions in Turkey.

5

Weak disposability in the non-parametric analysis of efficiency : an interval abatement factor

Maghbouli Mahnaz, Yekta Azam Pourhabib, Jablonsky Josef

Operations Research and Decisions

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2024

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Vol. 34, No. 3

193--203

EN

The prevalent economic principle of weak disposability has been the foundation for studies in environmental assessment using data envelopment analysis (DEA). Recently, a shift from classic free disposability to weak disposability has been observed as an emerging trend for treating undesirable factors in research. Weak disposability is perceived to have significant analytical power in measuring the efficiency of decision-making units (DMUs). With the aim of decreasing of undesirable outputs, a non-radial model grounded on a non-uniform augment factor is presented. The application of this proposed model anticipates a suitable quantity for the decreasing of undesirable outputs. Concurrently, the model ensures a corresponding and satiable amount for reduction in undesirable outputs. Numerical instances illuminate the practicality and robustness of the proposed model and demonstrate its superior performance over its original counterpart.

6

Input allocative efficiencies for operation and maintenance of rural piped water supply systems in highland areas of Vietnam

Dinh Dao Van, Nguyen Phong Tung, Nguyen Tan Tiep, Carrard Naomi, Ngoc Minh Nguyen, Ton Nu Hai Au

Journal of Water and Land Development

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2024

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no. 61

1--10

EN

Strengthening the functioning of existing rural piped water supply systems is a critical strategy for ensuring household water security, particularly in water-scarce contexts. Improving operation and maintenance (O&M) of the systems is an important area of focus, commonly plagued by poor reliability and functionality over time. From an economic perspective, there is an opportunity to optimise O&M input efficiencies as a foundation for improved management. This paper presented challenges and opportunities to optimise O&M input efficiencies based on an analysis of water supply systems in Vietnam’s highland areas characterised by mountainous terrain and water scarcity. The analysis focused on state-based agencies for O&M given their mandate for restoring the inefficient systems and identified input norms for guidance on how to optimise O&M activities. We applied an input-oriented data envelopment analysis (DEA) model under constant returns to scale assumption to estimate technical, economic and allocative efficiencies. The results identified efficiency levels of 90%, 30% and 33% respectively. The study suggests a 10% reduction in general input amounts and identified efficient input target values reveal potential reduction rates for technical labour (12%), electricity (12%), as well as the technical and economic norms of technical labour (0.86 personday∙(100 m3)-1 water sold) and electricity (0.53 kWh∙m-1 water sold). The policy implications for O&M state-based agencies include the adoption of input-based contracting mechanisms, while the government is encouraged to approve water tariffs and provide compensation based on input items to promote water service supply as a public good in water-scarce and challenging areas.

7

The eco-efficiency of fisheries in EU countries

Piwońska Kalina, Kryszak Łukasz

Economics and Environment

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2024

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No. 2

art. no. 691

EN

The main goal of this article was to (1) assess the dynamics of eco-efficiency of fisheries in EU countries and its components and (2) identify potential sources of inefficiencies and efficiency surpluses through slack analysis. The hybrid data envelopment analysis (DEA) model was used for the 2008-2019 period. Progress in eco-efficiency was found among 11 countries (out of 23), but the average eco-efficiency index for the sample was 0.988. Differences in the levels and dynamics of eco-efficiency between the studied countries were mainly driven by the efficiency change component, i.e. internal factors. The largest input-saving potential was found in relation to number of employees and gross tonnage of the vessel, suggesting that sample countries deal with the problem of overinvestment and overstaffing. We also found that greenhouse gas emissions could be reduced by approximately a third.

PL

Głównym celem niniejszego artykułu była (1) ocena dynamiki eko-efektywności rybołówstwa w krajach UE i jej komponentów oraz (2) identyfikacja potencjalnych źródeł nieefektywności i nadwyżek efektywności poprzez analizę luzu. Zastosowano hybrydowy model analizy obwiedni danych (DEA) dla okresu 2008-2019. Postęp w zakresie eko-efektywności stwierdzono wśród 11 krajów (z 23), ale średni wskaźnik eko-efektywności dla próby wyniósł 0,988. Różnice w poziomach i dynamice eko-efektywności pomiędzy badanymi krajami wynikały głównie z komponentu zmiany efektywności, tj. czynników wewnętrznych. Największy potencjał w zakresie redukcji nakładów stwierdzono w odniesieniu do liczby pracowników i pojemności brutto statku, co sugeruje, że badane kraje borykają się z problemem przeinwestowania i nadmiernego zatrudnienia. Stwierdziliśmy również, że emisję gazów cieplarnianych można zmniejszyć o około jedną trzecią.

8

Slack-based efficiency assessment of electrical distribution regions in Ghana

Tengey Clement, Nwulu Nnamdi, Adepoju Omoseni, Longe Omowunmi Mary

Przegląd Elektrotechniczny

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2023

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R. 99, nr 11

94--99

EN

This paper used the Slack-based efficiency data envelopment analysis model (DEA) to assess the efficiency of electrical distribution regions (EDRs) in Ghana, using Electricity Company of Ghana as a case study, an analysis that had not been previously conducted on the ECG. Results showed that the efficiency dipped drastically in 2013, but improved from 2014 to 2016, stagnating in 2017 and dropping further in 2018. The consistency of the estimations was ensured by establishing the production frontier's form, variable returns to scale.

PL

W tym artykule wykorzystano oparty na Slack model analizy danych dotyczących wydajności (DEA) do oceny wydajności regionów dystrybucji energii elektrycznej (EDR) w Ghanie, wykorzystując Electricity Company of Ghana jako studium przypadku, analizę, która nie została wcześniej przeprowadzona na EKG Wyniki pokazały, że wydajność drastycznie spadła w 2013 r., ale poprawiła się od 2014 do 2016 r., stagnacja w 2017 r. i dalszy spadek w 2018 r. Spójność szacunków została zapewniona poprzez ustalenie postaci granicy produkcji, zmiennych korzyści skali.

9

Neutrosophic data envelopment analysis based on the possibilistic mean approach

Mohanta Kshitish Kumar, Sharanappa Deena Sunil, Mishra Vishnu Narayan

Operations Research and Decisions

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2023

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Vol. 33, No. 2

81--98

EN

Data envelopment analysis (DEA) is a non-parametric approach for the estimation of production frontier that is used to calculate the performance of a group of similar decision-making units (DMUs) which employ comparable inputs to produce related outputs. However, observed values might occasionally be confusing, imprecise, ambiguous, inadequate, and inconsistent in real-world applications. Thus, disregarding these factors may result in incorrect decision-making. Thus neutrosophic sets have been created as an extension of intuitionistic fuzzy sets to represent ambiguous, erroneous, missing, and inaccurate information in real-world applications. In this study, we have proposed a technique for solving the neutrosophic form of the Charnes–Cooper–Rhodes (CCR) model based on single-value trapezoidal neutrosophic numbers (SVTrNNs). The possibilistic mean for SVTrNNs is redefined and applied the Mehar approach to transforming the neutrosophic DEA (Neu-DEA) model into its corresponding crisp DEA model. As a result, the efficiency scores of the DMUs are calculated using different risk parameter values lying in [0, 1]. A numerical example is given to analyze the performance of the all India institutes of medical sciences and compared it with Abdelfattah’s ranking approach.

10

Assessing telecommunication contractor firms using a hybrid DEA-BWM method

Valizadeh Omid, Ghiyasi Mojtaba

Operations Research and Decisions

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2023

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Vol. 33, No. 4

189--200

EN

Telecommunication companies have an important role in technology development, so evaluating the performance of these companies has been an interest of managers. This article uses a hybrid method using data envelopment analysis (DEA) and the best-worst method (BWM) to measure the performance of communication companies. The hybrid DEA-BWM method is used for the weight determination and performance assessment of 17 telecommunication contractor firms in the Khorsan Razavi province of Iran. We considered four inputs: gross losses, sales cost, legal reserve, and fixed assets. On the other side, three outputs including operation income, operation profit, and retained earnings are considered as outputs. Considering the input-output parameters and using the hybrid method by seven selected criteria, we rank all contractor firms. We found that the BPM firm has the best performance while and GKS firm is found as the firm with the weakest performance. Compared with the classical DEA methods, we found more reliable results with higher discrimination power, using the hybrid DEA-BWM.

11

Transport carbon emissions reduction efficiency and economic growth: a perspective from nighttime lights remote sensing

Yan Yuxiang, Li Jianing

Archives of Transport

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2023

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Vol. 66, iss. 2

21--32

EN

The carbon emissions are essential for climate change and 26% of the world's carbon emissions are related to transport. But focusing only on fewer carbon emissions might be biased at times. In order to keep a balance between economic growth and carbon emissions reduction, this paper evaluated the performance of carbon control by considering the input factors and output factors together, which is more comprehensive and reliable. Firstly, this paper has calculated the transport carbon emissions reduction efficiency (TCERE) based on the model of super SBM with undesirable outputs. The input factors include capital stock, labor force and fossil energy consumption. And the output factors include gross domestic product and carbon dioxide emissions. Then the influencing factors of TCERE were analyzed using econometric models. The economic growth, transport structure, technology level and population density were posited as influencing factors. This paper creatively proposed the per capita nighttime lights brightness as a new indicator for economic growth. An empirical study was conducted in East China from 2013 to 2017, and this study has found that the relationship between TCERE and economic growth shows an U-shape. Besides, transport structure and technology level both show a positive impact on TCERE. The implications of our findings are that: (a) The TCERE declines slower in East China, giving us reason to believe that the improvement of TCERE is predictable; (b) When economic growth exceeds the turning point, economic growth is conducive to the improvement of TCERE. We could develop the economy boldly and confidently; (c) Increased investment in railway and waterway transportation infrastructure projects is needed to strengthen the structure of the railway and waterway transportation systems. Furthermore, the general public and businesses should be encouraged to prefer rail or river transportation; (d) Investment in scientific and technological innovation should be enhanced in order to produce more efficient energy-use methods.

12

A slacks-based nonlinear DEA model with integer data : an application to departments of the Islamic Azad University, Karaj Branch in Iran

Moazenzadeh Zahra, Saati Saber, Saen Reza Farzipoor, Matin Reza Kazemi, Sohraee Sevan

Operations Research and Decisions

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2022

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Vol. 32, No. 3

80--91

EN

Although Data Envelopment Analysis (DEA) assumes that inputs and outputs take non-negative real values, in some realworld cases, data are integer-valued. In some situations, rounding a fractional value to the closest integer can lead to a misleading evaluation of efficiency and in some cases may lead to an infeasible projection point. To date, various radial and non-radial models have been presented. This paper proposes a slacks-based non-linear model that guarantees an integer-valued reference point for all integer targets. Also, the reference point of each target is feasible under the proposed model. The lack of a need to round answers to the closest whole value is an advantage of this method. In addition, the results of this model are compared with other models. An example is used to clarify the suggested method.

13

An application of the Negative Malmquist model for Vietnamese garment and textiles industry

Nguyen Thi Kim Lien, Nguyen Xuan-Huynh, Pham Hong V.

Management Systems in Production Engineering

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2022

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nr 1 (30)

74--79

EN

The study purpose is to measure the performance of the Vietnamese garment and textiles industry by means of the Negative Malmquist model using the data envelopment analysis (DEA) method. The empirical results presented the efficient, inefficient cases, and average efficiency for all garment and textile companies in Vietnam during from 2016 to 2020. The main findings determined that five companies, including HTG, TET, MSH, M10, and BDG possessed efficiency scores in whole terms. An overall picture of the garment and textiles industry in Vietnam is used to evaluate the operational process. The research recommends a feasible alternative method to deal with inefficient cases.

14

Input Use Efficiency in Operational and Maintenance Management of Small-Pumping Scale Irrigation Systems in Red River Delta, Vietnam

Dinh Dao Van, Nguyen Phong Tung, Tran Dat Van, Mukheibir Pierre, Ton Au Nu Hai

Journal of Ecological Engineering

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2022

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Vol. 23, nr 5

207--215

EN

In the Red River Delta (RRD) of Vietnam, small-pumping systems are one of main systems for paddy irrigation. It is imperative to analyze the operation and maintenance performance of irrigation systems by using the input factors when applying pricing mechanisms in the irrigation sector in Vietnam. In this study, based on the data of 48 irrigation systems managed by teams under irrigation companies, the non-parametric program, Data Envelopment Analysis, was used to measure the technical efficiency and scale efficiency for small-pumping scale irrigation systems in the Red River Delta. The seven input factors were the annual direct and indirect labor, materials, electricity, recurrent maintenance, overhead, and depreciation cost, and an output factor was the paddy areas irrigated by the systems. The results demonstrated that the average technical efficiency scores under constant returns to scale and variable returns to scale were 0.924 and 0.946, respectively. Thus, the wasted inputs were suggested to be 7.6% and 5.4% of the current input level, respectively. The average scale efficiency score was 0.977 and therefore, some 72.9% of the Decision-Making Units should adjust their input scales to achieve the efficiency in input factors.

15

Zróżnicowanie efektywności sektora towarowego transportu drogowego w Unii Europejskiej

Domagała Joanna, Borkowski Maciej

Gospodarka Materiałowa i Logistyka

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2022

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nr 7

24--31

PL

Celem artykułu jest określenie i porównanie efektywności sektorów towarowego transportu drogowego w krajach UE przy wykorzystaniu metody Data Envelopment Analysis (DEA). DEA jest wielowymiarową metodą badania efektywności, umożliwiającą porównanie wielu efektów z wieloma nakładami. W ramach badań obliczono model DEA ukierunkowany na maksymalizację efektów. Jako efekty uwzględniono: przychody sektora transportu drogowego (mln euro) oraz pracę przewozową (tkm), zaś jako nakłady uwzględniono: zatrudnienie (tys. os.); długość sieci drogowej (km); zużycie energii (Mtoe); zarejestrowane pojazdy ciężarowe (szt.). Wyniki badań wskazują, że 10 z 28 badanych sektorów transportu w UE było w pełni efektywnych. Dla sektorów nieefektywnych, bazując na koncepcji benchmarkingu, zaproponowano zmiany w poziomie efektów.

EN

The aim of the article is to use the Data Envelopment Analysis method to determine the efficiency of the road freight transport sectors in EU countries. The DEA method is a multidimensional efficiency tool that allows researchers to compare multiple effects with multiple inputs. As part of the research, the DEA model aimed at maximizing the effects was calculated. The outputs included: turnover of the road transport sector and payload-distance (tonne-kilometers), while the inputs included: employment; length of road network; energy consumption; registered trucks. Research results show that 10 out of 28 analyzed transport sectors in the EU were efficient. For ineffective sectors, based on the concept of benchmarking, changes in the level of effects have been proposed.

16

Performance analysis in the presence of bounded, discrete and flexible measures

Kordrostami Sohrab, Jahani Sayyad Noveiri Monireh

Operations Research and Decisions

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2021

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Vol. 31, No. 3

41--66

EN

In conventional data envelopment analysis (DEA) models, the relative efficiency of decision- -making units (DMUs) is evaluated while all measures with certain input and/or output status are considered as continuous data without upper and/or lower bounds. However, there are occasions in realworld applications that the efficiency of firms must be assessed while bounded elements, discrete values, and flexible measures are present. For this purpose, the current study proposes DEA-based approaches to estimate the relative efficiency of DMUs where bounded factors, integer values, and flexible measures exist. To illustrate it, radial models based on two aspects, individual and aggregate, are introduced to measure the performance of entities and to handle the status of the flexible measure such that there are bounded components and discrete data. Applications of approaches proposed in the areas of quality management, highway maintenance patrols, and university performance measurement are given to clarify the issue and to show their practicability. It was found that the introduced procedure can determine practical projection points for bounded measures and integer values (from the individual DMU viewpoint) and can classify flexible measures along with evaluation of DMUs relative efficiency.

17

Forecasting the confidence interval of efficiency in fuzzy DEA

Kafi Azarnoosh, Daneshian Behrouz, Rostamy-Malkhalifeh Mohsen

Operations Research and Decisions

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2021

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Vol. 31, No. 1

41--59

EN

Data envelopment analysis (DEA) is a well-known method that based on inputs and outputs calculates the efficiency of decision-making units (DMUs). Comparing the efficiency and ranking of DMUs in different periods lets the decision-makers prevent any loss in the productivity of units and improve the production planning. Despite the merits of DEA models, they are not able to forecast the efficiency of future periods with known input/output records of the DMUs. With this end in view, this study aims at proposing a forecasting algorithm with a 95% confidence interval to generate fuzzy data sets for future periods. Moreover, managers’ opinions are inserted in the proposed forecasting model. Equipped with the forecasted data sets and concerning the data sets from earlier periods, this model can rightly forecast the efficiency of the future periods. The proposed procedure also employs the simple geometric mean to discriminate between efficient units. Examples from a real case including 20 automobile firms show the applicability of the proposed algorithm.

18

Detecting congestion in DEA by solving one model

Shadab Maryam, Saati Saber, Farzipoor Saen Reza, Khoveyni Mohammad, Mostafaee Amin

Operations Research and Decisions

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2021

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Vol. 31, No. 1

77--96

EN

The presence of input congestion is one of the key issues that result in lower efficiency and performance in decision-making units (DMUs). So, determination of congestion is of prime importance, and removing it improves the performance of DMUs. One of the most appropriate methods for detecting congestion is Data Envelopment Analysis (DEA). Since the output of inefficient units can be increased by keeping the input constant through projecting on the weak efficiency frontier, it is unnecessary to determine the congested inefficient DMUs. Therefore, in this case, we solely determine congested vertex units. Towards this aim, only one LP model in DEA is proposed and the status of congestion (strong congestion and weak congestion) obtained. In our method, a vertex unit under evaluation is eliminated from the production technology, and then, if there exists an activity that belongs to the production technology with lower inputs and higher outputs compared with the omitted unit, we say vertex unit evidences congestion. One of the features of our model is that by solving only one LP model and with easier and fewer calculations compared to other methods, congested units can be identified. Data set obtained from Japanese chain stores for a period of 27 years is used to demonstrate the applicability of the proposed model and the results are compared with some previous methods.

19

DEA-based competition strategy in the presence of undesirable products : an application to paper mills

Amirteimoori Alireza, Masrouri Simin

Operations Research and Decisions

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2021

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Vol. 31, No. 2

5--21

EN

In real applications of data envelopment analysis (DEA), there are cases in which undesirable outputs are produced along with desirable outputs in such a way that the total sum of the produced undesirable outputs over the production units must be fixed and constant. In this case, a trade-off between the decision-making units (DMUs) is needed to balance the production of undesirable outputs. In a rational sight, this trade-off is done in such a way that all DMUs improve their relative performances. In this paper, a single DEA-based model is proposed to model fixed and variable-sum undesirable outputs in production processes. A common equilibrium efficient frontier is constructed and after reallocating the input/output factors, all decision-making units (DMUs) prevail as efficient. A real case of 32 paper mills in China is given. The results of the analysis demonstrated that some economically developed paper mills have better performance than less developed paper mills; in particular, all efficient paper mills are the developed ones.

20

A compositional approach to two-stage Data Envelopment Analysis in intuitionistic fuzzy environment

Javaherian Nafiseh, Hamzehee Ali, Tooranloo Hossein Sayyadi

Operations Research and Decisions

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2021

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Vol. 31, No. 1

21--39

EN

Classical methods of data envelopment analysis operate by measuring the efficiency of decision- -making units (DMUs) compared to similar units, without taking their internal structure into account. However, some DMUs consist of two stages, with the first stage producing an intermediate product, which is then consumed in the second stage to produce the final output. The efficiency of this type of DMU is often measured using two-stage network data envelopment analysis. In real world, most data are vague. Therefore, the inputs and outputs of systems with vagueness data create uncertainty challenges for DMUs. As a result, when uncertainty appears, intuitionistic fuzzy sets can show more information than classical fuzzy sets. This paper presents a model of two-stage Network Data Envelopment Analysis based on intuitionistic fuzzy data, which measures the efficiency of the first and second stages of each DMU, and the overall efficiency measures based on the stage efficiencies.