European Journal Of Operational Research Research Articles

Operational research in seven decades

This paper is an account and reflection on the author’s engagement with operational research (OR) starting in the 1960s with work in the glass industry coinciding with a PhD at Lancaster and a first encounter with the professional membership debate. The 1970s included a brief encounter with stochastic programming, soft OR which recurred throughout the decades, and the start of research into strategy support. The latter continued in the 80s and beyond and work on data envelopment analysis (DEA) began. In the 1990s, a strong DEA team was built at Warwick, and the author led the development of the OR Society’s fellowship scheme. In the 2000s a group met regularly at Warwick focussing on strategic development and leading to a book on strategy support and editing of the European Journal of Operational Research (EJOR) began. In the 2010s editing continued and work began on the contribution of the founders of OR to soft OR and practice. Editing wound down in the 2020s and the founders paper was published in the journal Operations Research.

Corrigendum to “Labeling methods for partially ordered paths” [European Journal of Operational Research 318 (2024) 19–30]

Corrigendum to “Labeling methods for partially ordered paths” [European Journal of Operational Research 318 (2024) 19–30]

Evaluation of the effectiveness of psychosocial rehabilitation: an innovative approach based on the analytic hierarchy process

IntroductionIn psychosocial rehabilitation (PSR), rank scales are widely used to assess the severity of functional disorders in patients. The main problem of evaluating the effectiveness of PSR is related to the methods of processing data obtained using psychometric scales used to evaluate the effectiveness of interventions within PSR. The proof of the non-numerical nature of ranks was obtained by J. Pfanzagl (1968). Incorrect processing of rank information obtained in the framework of psychosocial research leads to contradictions in the assessment of the patient’s condition. Consequently, rank processing does not allow classical mathematical operations (summation, average), which makes it impossible to correctly estimate the effectiveness of PSR numerically.ObjectivesDevelopment of algorithms for numerical evaluation of PSR efficiency based on rank information processing using the analytic hierarchy process (AHP) [1].MethodsClinical, psychometric, AHP algorithmsResultsThe analysis of the problems of assessing the patient’s conditions on the basis of categorical and psychometric (rank) scales and subscales shows that these problems can be presented in the form of appropriate hierarchies, the structure of which must be taken into account when processing the initial information.According to the results of the analysis of the data of preliminary studies, the main areas of impaired functioning of patients affecting the evaluation of the effectiveness of PSR have been identified. Rank estimates of changes in the relevant areas of the patient’s dysfunction after the PSR program compared to the initial level are the basis for the conclusion about the effectiveness of the PSR components. Algorithms of the AHP normative approach were used to translate rank information into numerical information [2]. The weight of the areas of the patient’s functioning disorders was used in the formation of integral estimates of the effectiveness of PSR.The fundamental difference between AHP-based assessments and rank assessments is due to the fact that numerical estimates of the weight of the criteria and the corresponding changes in the patient’s condition are obtained, which depend on the qualifications of specialists, the characteristics of the scales used to measure violations in the relevant areas and the procedures of the PSR.ConclusionsObtaining the results of processing rank information in a numerical scale allows to obtain the correct integration of the patient’s personal characteristics when considering PSR procedures and to obtain correct prognostic models of the patient’s condition. 1. Saaty T. European Journal of Operational Research.1990; 48(1):9-26. https://doi.org/10.1016/0377-2217(90)90057-I 2. Mitikhin V.G., Solokhina T.A. et al. Psychiatry, 2022; 20(2): 51-59. DOI: 10.30629/2618-6667-2022-20-2-51-59Disclosure of InterestNone Declared

Personalized assessment of the effectiveness of psychosocial rehabilitation: an innovative approach based on the process of analytical hierarchy

IntroductionIn psychosocial rehabilitation (PSR), rank scales are widely used to assess the severity of functional disorders in patients. The main problem of evaluating the effectiveness of PSR is related to the methods of processing data obtained using psychometric scales used to evaluate the effectiveness of interventions within PSR. J. Pfanzagl (1968) obtained the proof of the non-numerical nature of ranks. Incorrect processing of rank information obtained in the framework of psychosocial research leads to contradictions in the assessment of the patient’s condition. Consequently, rank processing does not allow classical mathematical operations (summation, average), which makes it impossible to correctly estimate the effectiveness of PSR numerically.ObjectivesDevelopment of algorithms for numerical evaluation of PSR efficiency based on rank information processing using the analytic hierarchy process (AHP) [1].MethodsClinical, psychometric, AHP algorithms.ResultsThe analysis of the problems of assessing the patient’s conditions on the basis of categorical and psychometric (rank) scales and subscales shows that these problems can be presented in the form of appropriate hierarchies [2], the structure of which must be taken into account when processing the initial information.According to the results of the analysis of the data of preliminary studies, the main areas of impaired functioning of patients affecting the evaluation of the effectiveness of PSR have been identified. Rank estimates of changes in the relevant areas of the patient’s dysfunction after the PSR program compared to the initial level are the basis for the conclusion about the effectiveness of the PSR components. Algorithms of the AHP normative approach were used to translate rank information into numerical information [2]. The weight of the areas of the patient’s functioning disorders was used in the formation of integral estimates of the effectiveness of PSR.The fundamental difference between AHP-based assessments and rank assessments is due to the fact that numerical estimates of the weight of the criteria and the corresponding changes in the patient’s condition are obtained, which depend on the qualifications of specialists, the characteristics of the scales used to measure violations in the relevant areas and the procedures of the PSR.ConclusionsObtaining the results of processing rank information in a numerical scale allows to obtain the correct integration of the patient’s personal characteristics when considering PSR procedures and to obtain correct models of the patient’s state. 1. Saaty T. European Journal of Operational Research.1990; 48(1):9-26. https://doi.org/10.1016/0377-2217(90)90057-I 2. Mitikhin V.G., Solokhina T.A. et al. Psychiatry, 2022; 20(2): 51-59. DOI: 10.30629/2618-6667-2022-20-2-51-59Disclosure of InterestNone Declared

Corrigendum to ‘Self-adjusting the tolerance level in a fully sequential feasibility check procedure’ [European Journal of Operational Research, Volume 272, Issue 2, December 2018, Pages 733–745

Corrigendum to ‘Self-adjusting the tolerance level in a fully sequential feasibility check procedure’ [European Journal of Operational Research, Volume 272, Issue 2, December 2018, Pages 733–745

A note on “A unified solution framework for multi-attribute vehicle routing problems”

In this note, the authors propose correcting one erroneous formula from [Vidal, T., Crainic, T. G., Gendreau, M., & Prins, C. (2014). A unified solution framework for multi-attribute vehicle routing problems. European Journal of Operational Research, 234(3), 658–673] in charge of lunch breaks. In the original paper, the authors propose to compute several attribute values from the solution of a vehicle routing problem; like the earliest and latest starting time for sequences of customers to visit. The computed values allow us to quickly evaluate the feasibility and the marginal cost of some neighbor solutions. Several variants of the class of vehicle routing problems can be addressed using this approach. In the case of drivers’ lunch break scheduling, the proposed formula combines optimistic values for the earliest and the latest completion times of the sequence of customers to visit. Using these values to evaluate neighbor solutions, may conclude that unfeasible solutions are feasible, or underestimate the completion time of a driver’s route. In this note, we describe a counter-example to identify the error in the formula. We also adapt the formula to the correct result.

Mapping the Evolution of the European Union Retail Supply Chain Technology Management: A Bibliometric Analysis

Effective supply chain management (SCM) technology is crucial for the success of retail businesses in the European Union (EU). This research thesis aims to employ bibliometric analysis to provide a comprehensive examination of global contributions and contemporary keyword trends in the field of SCM technology within the EU. Using the Web of Science database, a systematic search was conducted, resulting in a total of 3,173 relevant articles. Bibliometric Analysis and VOSviewer (VOS) were employed to analyze the research landscape. The analysis shows that although this topic is based on the European Union, the scientific productivity and influence on the topic from China, Britain and the United States are higher than that of many EU countries. The European Journal of Operational Research emerged as the most influential journal in terms of both productivity and impact. Affiliations primarily consisted of universities, with a significant contribution from five universities showing consistent growth in research productivity. The results of Network visualization and Thematic Map analysis results of keywords show that technology-based red keyword clustering is very important for the research in this field, including demand response, microgrids, algorithms, price, policies, simulation and so on. This analysis highlights the importance of technology-related topics in the supply chain of EU retailers.

BOUNDED STRATEGIES FOR MAXIMIZING THE SHARPE RATIO

Bernard et al. [(2019) Optimal strategies under omega ratio, European Journal of Operational Research 275 (2), 755–767] use convex ordering arguments to determine the bounded payoff for maximizing the omega ratio. However, it appears difficult to apply such reasoning to estimate the bounded payoff for maximizing the Sharpe ratio. As a proposed solution, this paper uses a Lagrange multiplier method to derive the bounded payoff for maximizing the Sharpe ratio. In contrast to the optimal strategy in Bernard & Vanduffel [(2014) Mean–variance optimal portfolios in the presence of a benchmark with applications to fraud detection, European Journal of Operational Research 234 (2), 469–480], the optimal strategy in this paper is bounded from below. It can protect investors from substantial losses when they invest in payoffs with a maximized Sharpe ratio.

On second order cone programming approach to two-stage network data envelopment analysis

In two recent papers, [Guo, C., Wei, F., & Chen, Y. (2017). A note on second order cone programming approach to two-stage network data envelopment analysis. European Journal of Operational Research, 263(2), 733–735; and Chen, K., & Zhu, J. (2017). Second order cone programming approach to two-stage network data envelopment analysis. European Journal of Operational Research, 262(1), 231238] converted the general multiplicative two-stage DEA (data envelopment analysis) network model into a parametric/single second order conic programming (SOCP) problem. In this paper, we (i) note that the proposed transformation cannot result in an equivalent mathematical program in view of the fact that the general multiplicative two-stage DEA model is basically a nonconvex optimisation problem, possibly with several local and global optimums, whereas a single SOCP is a convex optimisation; (ii) demonstrate that there is a subtle technical error contained in the main transformation process proposed in both papers; (iii) illustrate, by providing a numerical counterexample, that the optimal solution obtained from the resulting single SOCP problem might be substantially different from the original model’s optimum; and (iv) offer some computational remark for solving the multiplicative/additive two-stage DEA model.

Advancing the marketing‐operations interface in omnichannel retail

Advancing the marketing‐operations interface in omnichannel retail

An information system success model for e-learning postadoption using the fuzzy analytic network process.

The underutilization of e-learning among university lecturers is an important issue that needs to be resolved. This study aimed to formulate an e-learning postadoption model for Malaysian universities. Data were collected using self-administered questionnaires involving 36 e-learning experts who from lecturers in public and private universities in Malaysia. The data collected was then analyzed using the extent analysis method proposed by Chang (European Journal of Operational Research, 95(3), 649-655, 1996) to examine the weights and rankings of the factors and subfactors. This study showed that for e-learning postadoption, the most important factor is institution service quality, followed by system quality, content quality, instructors' characteristics, and learners' characteristics. This study extends the information systems success model into the e-learning postadoption context. In particular, this study offered insights concerning the dependencies among the factors in the model within the Malaysian university context. The findings are useful for the long-range strategic management of university administrators, and the model can be adopted as a reference to form a rating system to analyze e-learning postadoption. University administrators can analyze critical factors that increase e-learning's post adoption and lead to more efficient resource allocation and management of e-learning.

Strategic investment under uncertainty in a triopoly market: Timing and capacity choice

This paper analyzes investment decisions under uncertainty in a triopoly market. We determine the investment timing and the investment size of the firms under the condition that firms hold an asymmetric cost structure. We build on Shibata (European Journal of Operational Research, 2016) who solves this problem with exogenous investment size. He finds that the firm with the lowest cost does not always enter the market as the first investor. However, we obtain that, when extending the analysis for capacity choice, the firm with the lowest cost always enters first in the triopoly market. The designed algorithm, which employs the bisection method at several steps to solve this model, is of value of its own as it can be more generally applied to investment problems in markets with several firms and multiple investment opportunities.

Some comments on Russell graph efficiency measures in data envelopment analysis: The multiplicative approach

In a recently published paper, Alcaraz, J., Anton-Sanchez, L., Aparicio, J., Monge, J. F., & Ramón, N., 2021. Russell graph efficiency measures in Data Envelopment Analysis: The multiplicative approach. European Journal of Operational Research, 292(2), 663–674, propose multiplicative versions of Russell-type graph efficiency measures based on geometric aggregations of input and output efficiency measures. Within the data envelopment analysis framework, they devise an iterative algorithm to solve the multiplicative models via a second order conic programming approach. In this paper, we demonstrate that the proposed models are not convex and reformulate them as two equivalent well-known types of nonconvex optimisation problems. By providing a numerical counterexample, we illustrate that their proposed algorithm may stop at a local optimum rather than converging to a global optimal solution. Some computational remarks are further suggested in regard to solving the proposed models.

Introduction to the Special Subsection: Contemplating the BICS Essay Contest on Postmortem Survival

Well-known aerospace entrepreneur Robert T. Bigelow has contributed a great deal privately and publicly to science and technology over the years, including the realm of anomalistics and edge science [see: Kelleher, C. A., & Knapp, G. (2005). Hunt for the skinwalker: Science confronts the unexplained at a remote ranch in Utah. Paraview Pocket Books]. This generous support should be celebrated, as it is virtually unique in modern times where academic freedom and consequential funding are sparse in the controversial fields that JSE routinely spotlights. In fact, Bigelow recently formed the Bigelow Institute of Consciousness Studies (BICS) to support research on the ostensible survival of human consciousness after physical death and the potential nature of such a state. BICS therefore comprises an ongoing platform for exploration and education versus a singular act of support from a lone patron. Among the organization’s first initiatives was a global campaign to solicit the best evidence supporting the notion of postmortem survival. This venture paralleled successful ‘crowdsourcing contests’ that some companies use to drive product improvements or innovations via public competitions with cash awards [see: Segev, E. (2020). Crowdsourcing contests. European Journal of Operational Research, 281, 241–255. https://doi.org/10.1016/j.ejor.2019.02.057 ].

Forecast combination-based forecast reconciliation: Insights and extensions

In this paper, we build upon a recently proposed forecast combination-based approach to the reconciliation of a simple hierarchy (Hollyman R., Petropoulos F., Tipping M.E., Understanding forecast reconciliation, European Journal of Operational Research, 2021, 294, 149–160) and extend it in some new directions. In particular, we provide insights into the nature and mathematical derivation of the level-l conditional coherent (LlCC) point forecast reconciliation procedure for an elementary two-level hierarchy. We show that: (i) the LlCC procedure is the result of a linearly constrained minimization of a quadratic loss function, with an exogenous constraint given by the base forecast of the top level series of the hierarchy, which is not revised; and (ii) endogenous constraints may also be considered in the same framework, thereby resulting in level conditional reconciled forecasts where both the top and the bottom level time series forecasts are coherently revised. In addition, we show that the LlCC procedure (i.e., with exogenous constraints but the result also holds in the endogenous case) does not guarantee the non-negativity of the reconciled forecasts, which can be an issue in cases when non-negativity is a natural attribute of the variables that need to be forecast (e.g., sales and tourism flows). Finally, we consider two forecasting experiments to evaluate the performance of various cross-sectional forecast combination-based point forecast reconciliation procedures (vis-à-vis the state-of-the-art procedures) in a fair setting. In this framework, due to the crucial role played by the (possibly different) models used to compute the base forecasts, we re-interpret the combined conditional coherent reconciliation procedure (CCCH) of Hollyman et al. (2021) as a forecast pooling approach, and show that accuracy improvements may be obtained by adopting a simple forecast averaging strategy.

Myopic vs. foresighted behaviors in a transboundary pollution game with abatement policy and emission permits trading

In this paper, we extend the model proposed in Benchekroun, H. and Martin-Herran, G. (2016). The impact of foresight in a transboundary pollution game. European Journal of Operational Research, 251(1), 300–309, to a more general one, in which emission permits trading and abatement policy are taken into consideration, to examine the effect of foresight on the optimal emission levels and optimal abatements in a transboundary industrial pollution game. In our model, a foresighted country chooses strategies to maximize the long-term payoff, while a myopic player ignores the impact of his decisions on the future evolutions of payoff and pollution stock. Considering the emission permits price and abatement costs, we obtain the abatement levels, the emission levels, the value functions, and the trajectories of pollution stocks of the farsighted and myopic countries, respectively. Consisting with the previous, our results show that the revenues obtained from farsighted behavior are larger than those from myopia, and the total emission of myopic countries is more than that of the farsighted ones. The total emissions will decrease with the increasing of abatement cost coefficients and emission permits price. New results are from two aspects. On the one hand, for a myopic country, the larger the abatement cost coefficients are, the smaller the willingness to acquire foresight is. On the other hand, when a myopic country acquires foresight, the other myopic countries still do not implement the abatement, while the farsighted countries should improve their abatement levels.

Scientific knowledge graph and trend analysis of operation management: A bibliometric analysis

Operation management, which has always been a hot topic in management research for seeking to increase the efficiency of the system using scientific methods. We use the Web of Science database to select the pertinent literature data from 2012 to 2022 with a focus on 10 significant international journals to perform the scoped literature on operation management in this paper. It then conducts a bibliometric analysis of operation management from two perspectives—main direction and development trend—using CiteSpace and VOSviewer. The analysis discovered that between 2012 and 2022, 22952 papers on operation management were published in significant international journals. Of these, 4398 were written by Chinese academics, making up 19.16% of the total. International Journal of Production Research, European Journal of Operational Research, and International Journal of Production Economics were the main venues for Chinese academics' publications. The National Natural Science Foundation of China supported 3446 papers in these journals, or 15.01% of all papers published. A variety of research hotspots are revealed by keyword analysis. The research's findings provide an excellent framework for describing the traits and developments in operation management.

INFLATION, CENTRAL BANK AND SHORT-TERM INTEREST RATES: A NEW MODEL WITH CALIBRATION TO MARKET DATA

In this paper, we propose a new model for the joint evolution of the inflation rate, the Central Bank official interest rate and the short-term interest rate. Our model takes into account the fact that the Central Bank interest rate changes at random times, inflation is measured at fixed, regular times, while the short-term interest rate evolves essentially continuously. We derive the valuation equation for a contingent claim and show that it has a unique solution. The payoff may depend on all three economic factors of the model and the discount factor is allowed to include inflation. Our model is not an affine model. Although in some special cases the solution of the valuation equation might admit a closed form, in general it has to be solved numerically. This can be done efficiently by the algorithm that we provide. Taking as a benchmark the model of [H. W. Ho, H. H. Huang & Y. Yildirim (2014) Affine model of inflation-indexed derivatives and inflation risk premium, European Journal of Operational Research 235, 159–169], we show that our model performs better on European market data from 2008 to 2015. Our model uses many fewer parameters than the benchmark model: This is advantageous from the numerical point of view and suggests that our model describes the behavior of the economic factors more closely.

On the properties of lexicographic tolerable robust solution sets for uncertain multi-objective optimization problems

This study provides the important properties of the lexicographic tolerable robust solution for uncertain multi-objective optimization problems which was introduced by Boriwan et al. [Boriwan, P.; Ehrgott, M.; Kuroiwa, D.; Petrot, N. The lexicographic tolerable robustness concept for uncertain multi-objective optimization problems: a study on water resources management. Sustainability. 12 (2020), no. 18, article number 7582.]. Also, the relationship between the lexicographic tolerable solution concept and the well-known robust solution, as the set-based robust efficiency [Ehrgott, M.; Ide, J.; Schöbel, A. Minmax robustness for multi-objective optimization problems. European Journal of Operational Research. 239 (2014), no. 1, 17-31.], are provided.

Robustness of efficiency scores in data envelopment analysis with interval scale data

Our paper focuses on a robustness analysis of efficiency scores in the context of Data Envelopment Analysis (DEA) assuming interval scale data, as defined in A. Dehnokhalaji, P. J. Korhonen, M. Köksalan, N. Nasrabadi and J. Wallenius, “Efficiency Analysis to incorporate interval scale data”, European Journal of Operational Research 207 (2), 2010, pp. 1116–1121. We first show that the definition of the efficiency score used in our paper is a well-defined measure according to Aparicio and Pastor (J. Aparicio and J. T. Pastor, “A well-defined efficiency measure for dealing with closest targets in DEA”, Applied Mathematics and Computation 219 (17), 2013, pp. 9142–9154.). Next, we characterize how robust the efficiency scores are with respect to improvements and deteriorations of inputs and outputs. We illustrate our analysis with two examples: a simple numerical example and a more complex example using real-world data.