Omega-international Journal of Management Science最新文献

{"title":"Accounting for caseloads in the efficiency analysis of courts of justice","authors":"Grammatoula Papaioannou ,&nbsp;Panagiotis Ravanos ,&nbsp;Giannis Karagiannis ,&nbsp;Victor V. Podinovski","doi":"10.1016/j.omega.2025.103401","DOIUrl":"10.1016/j.omega.2025.103401","url":null,"abstract":"<div><div>Many reported applications of data envelopment analysis to courts of justice raise the issue of treatment of caseloads, consisting of the backlog of yet unresolved cases transferred from the previous year and new incoming cases. A common approach, which has some known drawbacks, is to incorporate caseloads as inputs in the model. In this paper, we propose a different methodology addressing this issue. We first assess the efficiency of courts disregarding caseloads and then decompose it into the product of two measures. One is the resolution rate that shows the proportion of caseload (capped by the boundaries of the technology) resolved by the court. The second is the caseload sufficiency factor that reflects the potentially limiting effect of the caseload on the ability of the court to achieve its efficient target. This approach allows straightforward extensions to arbitrary production technologies and different efficiency measures. We illustrate the proposed methodology by an application to a sample of Greek county courts. We show that the proposed methodology has significantly higher discriminating power on court efficiency than the model with caseloads as inputs. It also provides more detailed information about the sources of inefficiency of courts than the latter common approach.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103401"},"PeriodicalIF":7.2,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Apportionment methods in resource allocation","authors":"László Á. Kóczy ,&nbsp;Tamás Koltai ,&nbsp;Balázs R. Sziklai","doi":"10.1016/j.omega.2025.103403","DOIUrl":"10.1016/j.omega.2025.103403","url":null,"abstract":"<div><div>The efficient use of resources is of paramount importance in any organization, and this is especially true of the use of human resources. We are considering an organization with a fixed number of workers over a network of subunits. The relative efficiency of these units can be uncovered using Data Envelopment Analysis (DEA) methods. How do we overcome efficiency differences when resources are constrained? Motivated by concerns for quality assurance, we use a method that lexicographically minimizes the tasks per worker. We present a fast algorithm to calculate the optimal allocation. Connections to the apportionment literature — mostly focusing on the fair allocation of voting districts among geographical or administrative regions, — are discussed. The allocation can be validated using DEA: efficiency indicators are now levelled.</div><div>The method is illustrated using data from salary administrators at the Hungarian State Treasury’s 19 county-level subsidiaries. Knowing the number of standard administrative tasks for each subsidiary and each month, we allocate workers proportionally to the busiest months. After the reallocation, the relative efficiency of the worst-performing counties moves from about 60% to over 90%.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103403"},"PeriodicalIF":7.2,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144756711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal self-scheduling and market involvement with electricity price uncertainty","authors":"Mengling Zhang ,&nbsp;Lun Ran ,&nbsp;Jianzhi Leng","doi":"10.1016/j.omega.2025.103372","DOIUrl":"10.1016/j.omega.2025.103372","url":null,"abstract":"<div><div>With increasing electricity market complexity and electricity price volatility, self-scheduling and market involvement problem has become a significant challenge for power producers. Instead of previous studies focusing solely on single-market optimization problem, we propose a self-scheduling and market involvement problem that integrates both the forward market and the spot market under price uncertainty. In our approach, the forward market determines unit commitment and electricity transaction decisions for future periods, while the spot market dictates generation scheduling and real-time electricity transaction. The objective is to maximize profit from both markets, while managing the risks associated with price uncertainty using the mean conditional value-at-risk (mean-CVaR). This risk measure captures the potential losses in profit over all spot price distributions, enabling a balance between profit maximization and risk aversion. To address electricity price uncertainty, we introduce two distributionally robust optimization (DRO) models. The first, M-DRO, utilizes the mean, support, and mean absolute deviation to define the ambiguity set, ensuring tractable and efficient optimization. The second, W-DRO, employs the 1-Wasserstein distance to capture more complex and data-driven uncertainties. A decomposition-based algorithm is proposed to solve the reformulated max–min problems. Extensive numerical experiments compare the performance of the proposed DRO models against traditional stochastic programming methods, providing key managerial insights for power producers in multi-market involvement.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103372"},"PeriodicalIF":6.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Competition or social priority? The subsidy strategies for the power sector amid power crisis","authors":"Ji Chen ,&nbsp;Xiangwen Li ,&nbsp;Xiao Yu ,&nbsp;Tomas Baležentis","doi":"10.1016/j.omega.2025.103402","DOIUrl":"10.1016/j.omega.2025.103402","url":null,"abstract":"<div><div>Frequent power crises disrupt the equilibrium of global economic systems, underscoring the critical need for effective sectoral subsidy policies to address energy shortages. Taking China's power crisis as an exogenous shock, this study investigates the impact of government subsidies during the crisis based on panel data from Chinese power enterprises from 2003 to 2007. Additionally, the optimal subsidy strategies are explored through the Bertrand competition model. The findings confirmed that government subsidies can effectively mitigate the adverse effects of power crisis on power enterprises and enhance total factor productivity (TFP). An increase in output scale and market power significantly promotes the TFP. Furthermore, an optimal implementation space exists that is defined by the degree of market competition. Deviating from this range leads to a divergence between the actual outcomes of the subsidy policy and the intended objectives set by policymakers. This study provides a systematic framework for optimizing subsidy strategies, offering valuable insights for other countries to address energy crises and broader disruptions in energy systems.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103402"},"PeriodicalIF":6.7,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Planning container flows through the Eurasian rail network: Managing ad-hoc demand under limited capacity","authors":"Jing Shan ,&nbsp;Jörn Schönberger","doi":"10.1016/j.omega.2025.103395","DOIUrl":"10.1016/j.omega.2025.103395","url":null,"abstract":"<div><div>In the post-COVID era, supply chain viability (SCV) has gained significant attention, requiring supply chains to be both resilient and adaptable to unforeseen disruptions. The Eurasian rail freight presents a viable alternative to complement traditional maritime shipping routes in times of disruption. A surge in ad hoc demand for Eurasian rail freight presents challenges to the network’s limited capacity and complex coordination across railway systems, exceeding the limits of current manual planning. Furthermore, converting the Eurasian rail freight system from a subsidy-driven model to a revenue-funded transport system is urgent. While revenue management plays a crucial role in optimizing transport networks, this area has received significantly less attention in the intercontinental rail freight industry compared to the airline sector. This paper develops the Revenue Management-Intercontinental Scheduled Service Network Design (RM-ISSND) model, a decision support system that aims to optimize revenue in intercontinental rail freight transport for ad hoc demands. The model supports intercontinental rail freight planning by identifying the most profitable ad hoc shipments while rejecting those that do not contribute to maximizing total revenue and are better suited for maritime or air transport. The RM-ISSND model also facilitates a shift from block routing (all containers in an order follow the same path), which is commonly used in Eurasian rail freight, to a new operational principle with free routing (containers in an order are free to be routed along different paths), enhancing both efficiency and profitability. Experiments show that prioritizing transit times between 27 and 35 days in the existing Eurasian rail freight network yields higher profits, underscoring the need to improve border crossing and main transit times to attract more time-sensitive ad hoc orders.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103395"},"PeriodicalIF":6.7,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144678924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust de novo programming under different uncertainty sets and its application to the renewable energy sector","authors":"Noureddine Kouaissah","doi":"10.1016/j.omega.2025.103389","DOIUrl":"10.1016/j.omega.2025.103389","url":null,"abstract":"<div><div>This paper proposes robust models of de novo programming (R-DNP) using cardinality-constrained robustness with interval-based, ellipsoidal, and norm-based uncertainty sets. R-DNP has not been researched or explored, and we aim to fill this gap in the literature. In particular, we develop the robust counterpart of the weighted DNP (W-DNP), Chebyshev DNP (C-DNP), and extended DNP (E-DNP) models to incorporate different uncertainty sets and decision-makers’ preferences. Methodologically, the proposed approach extends the conventional DNP model to solve uncertain coefficients for each decision variable on the left-hand side of each objective function and on the total budget, overcoming the limitations of the current multicriteria solution procedure of the DNP approach. The proposed methods provide decision-makers with more flexibility to express their level of conservatism and preferences by setting priority weights and aspiration levels. The proposed method’s usefulness over the standard DNP is demonstrated by providing an illustrative example. Moreover, we validate the proposed formulations for solving real-world problems through a hypothetical application: optimizing onshore wind farm locations in Morocco. The work’s results confirm the validity of the proposed methodologies, showing that they can assist decision-makers in determining the optimal system design for sustainable electricity generation under uncertain conditions.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103389"},"PeriodicalIF":6.7,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144678923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal production, fuel economy investment and credit trading decisions under dual-credit policy","authors":"Zhenxiao Wang ,&nbsp;Fen Xu ,&nbsp;Li Xiao ,&nbsp;Peng Yang","doi":"10.1016/j.omega.2025.103375","DOIUrl":"10.1016/j.omega.2025.103375","url":null,"abstract":"<div><div>We study a production system that produces FVs and NEVs during one selling season under the dual-credit policy (DCP), which is issued to reduce the greenhouse emissions generated from production. One specific feature of our model is that production generates two credits, either positive or negative, and DCP requires nonnegative credits at the end of the selling season and penalizes the negative credits. We show that the optimal production, fuel economy investment, and credit trading decisions depend on the initial capability of generating credits. Based on the optimal decisions, we find that DCP promotes the production of automakers who sell credits and reduces the production of automakers who purchase credits. We next discuss various factors affecting the optimal decisions and the effectiveness of DCP. In particular, a high initial capability to generate positive credits induces a high profit and large production quantity. A high credit purchasing price induces a low profit and a small credit trading volume. However, the optimal fuel economy decision and the credit trading decision are non-monotone in the initial capability to generate credits, and the production quantity and the fuel economy investment are non-monotone in the credit purchasing price.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103375"},"PeriodicalIF":6.7,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144611536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"To adopt or not? The impacts of “Try-Now-Pay-Later” on platform markets","authors":"Shuxiao Sun ,&nbsp;He Liu ,&nbsp;Jinrong Zhu ,&nbsp;Shouyang Wang","doi":"10.1016/j.omega.2025.103390","DOIUrl":"10.1016/j.omega.2025.103390","url":null,"abstract":"<div><div>“Try-Now-Pay-Later” (TNPL), which combines “Try Before You Pay” (TBYP) and “Buy Now, Pay Later” (BNPL), is a business model innovation launched by some platforms such as Klarna and Affirm in collaboration with retailers. It allows consumers to place an order for free and provides consumers with a free experience period to assess the product fit before finishing the payment. Under TNPL, cash flow occurs within platform markets (including platforms, retailers, and consumers), influencing purchasing decisions of consumers and operational decisions of platforms and retailers. This paper develops a game-theoretic model to investigate the impact of TNPL on platform operations in a market where a retailer sells through a platform. The retailer determines the retail price and pays a commission fee to the platform for each product sold, and either the retailer or consumers pay(s) for the return freight. The results show that (1) TNPL can increase both the retailer’s retail price and the platform’s commission rate, no matter who bears the return freight. (2) Compared to the traditional model, the retailer is most likely to benefit the most from TNPL, followed by consumers, with the platform benefiting the least. (3) If the retailer’s proficiency in handling returns is not significantly greater than that of consumers, especially when the proportion of defaulting consumers is larger and the opportunity cost of cash is lower, all three parties are better off when the return shipping cost is borne by consumers. (4) TNPL generates Pareto improvements when consumer utility enhancement is significant, the product matching rate is high, the proportion of defaulting consumers is small, and the cash opportunity cost is low. Furthermore, the impact of TNPL on competing platforms and retailers depends on the relative competitive advantages gained through consumers’ utility improvements. Our findings offer valuable insights for platforms and retailers on how to optimize their operational strategies to effectively leverage TNPL, thereby enhancing both business performance and social welfare.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103390"},"PeriodicalIF":6.7,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A branch-and-price algorithm for the parallel-line lot-sizing and scheduling problem in flat-panel display manufacturing process","authors":"Seyoung Oh ,&nbsp;Jinyeong Jeong ,&nbsp;Younsoo Lee ,&nbsp;Kyungsik Lee","doi":"10.1016/j.omega.2025.103386","DOIUrl":"10.1016/j.omega.2025.103386","url":null,"abstract":"<div><div>In this paper, we address a lot-sizing and scheduling problem with parallel production lines originating from a flat-panel display manufacturing process. Due to the use of high-tech equipment and expensive materials, as well as high demand levels, it is crucial to establish efficient production plans for this process. We present two integer optimization models for the problem. The first one is an extension of a model proposed in previous literature. Although the model shows satisfactory performance for problems with a single production line, it does not scale well with an increasing number of production lines. To address the scalability issue, we propose an integer optimization approach that can deal with parallel production lines efficiently. Specifically, we introduce a pattern-based model utilizing the concept of a single-line production schedule pattern. To deal with the exponential number of pattern variables in the model, we develop a branch-and-price algorithm. Additionally, we devise an efficient labeling algorithm to solve pricing subproblems, based on a time-expanded network structure of the problem. The performance of the proposed models and algorithms is investigated through computational experiments using real-world data. The test results demonstrate the effectiveness and efficiency of our approaches, particularly showing that the branch-and-price algorithm scales well with an increasing number of production lines.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103386"},"PeriodicalIF":6.7,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Randomized price-matching: How the instant retail platform competes with the community group-buying store","authors":"Chenchen Zhao ,&nbsp;Jianghua Wu ,&nbsp;Yuhong He","doi":"10.1016/j.omega.2025.103393","DOIUrl":"10.1016/j.omega.2025.103393","url":null,"abstract":"<div><div>Community group-buying, leveraging the “pre-sale + self-pickup” mode, has surged in recent years, offering competitive prices due to operational efficiency and cost-effectiveness, appealing to liberal customers. Nonetheless, conservative customers still favor instant retail platforms, prompting them to frequently cut prices amid emerging competition. Therefore, this study proposes a randomized price-matching (PM) strategy for instant retail platforms to increase their revenue. Under this strategy, the platform randomly decides whether to match the low prices offered by community group-buying stores in each sales period. Therefore, this study constructs a game-theoretical model to explore not only the impact of instant retail platforms’ randomized PM strategies on the pricing and profits of the two retailers but also how strategic customer behavior affects retailers’ pricing strategies. We find that the randomized PM strategy is not always optimal for the instant retail platform, especially when the utility loss from delayed purchases or customer acceptance of group-buying channels is small. Furthermore, the randomized PM strategy often leads the platform and group-buying store to increase their prices. However, it can result in a decrease in the group-buying store’s price when the proportion of liberal customers is small. Interestingly, this strategy has the potential to not only boost the platform’s profits but also benefit the community group-buying store, thus achieving win-win outcome. Furthermore, customer composition and characteristics affect pricing decisions. Specifically, under the randomized PM strategy, as customers’ acceptance of group-buying channels increases, the platform will raise the PM probability.</div></div>","PeriodicalId":19529,"journal":{"name":"Omega-international Journal of Management Science","volume":"138 ","pages":"Article 103393"},"PeriodicalIF":6.7,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}