European J. of Industrial Engineering (35 papers in press)

Regular Issues

• The impact of online sales in centralized and decentralized dual-channel supply chains  
  by Subrata Saha 
  Abstract: This paper studies a supply chain structure featuring two different types of distribution channels through which manufacturers sell products. The centralised and decentralised distribution channels considered in this study are affected by online sales outside the structured channels. In the centralised distribution channel, two retail stores located in geographically distinct markets are operated by a single owner. In the decentralised distribution channel, two retailers independently operate two retail stores. In the non-cooperative scenario, the manufacturer always prefers the decentralised distribution channel irrespective of whether an online channel is used. To achieve channel coordination, a revenue-sharing contract is applied, but it can be used to coordinate only the decentralised distribution system. Therefore, a modified revenue-sharing contract is proposed to coordinate the centralised distribution system. The analytical study reveals that without coordination among the channel members, the manufacturer always earns maximum profit in decentralised distribution systems. However, if the supply chain is coordinated, then the manufacturer receives more benefits from using the centralised distribution systems under certain conditions. Propositions are presented to describe the characteristics of distribution structures, and to provide meaningful management guidelines for coordinating them. Extensive numerical investigations are also presented.
  Keywords: Supply chain management; Dual-channel supply chain; Revenue sharing contract; Pricing strategy; Stackelberg.
  DOI: 10.1504/EJIE.2018.10011153
   
  
• Risk-Averse Joint Facility Location-Inventory Optimization for Green Closed-Loop Supply  
  by Guodong Yu, Pengcheng Dong, Ying Xu, Xiao Zhao 
  Abstract: This paper considers a joint facility location-inventory optimisation for green closed-loop supply chain network design under demand uncertainty. Under the uncoordinated inventory policy, we propose a chance-constrained risk-averse bi-objective 01 mixed-integer nonlinear stochastic programming to minimise the total expected cost and CO2 emissions. To solve the model, we first present an equivalent reformulation with a single objective based on distributionally robust optimisation. Then, we provide a linear reformulation with some valid inequalities. We also provide a greedy heuristic decomposition searching rule to solve the large-scale problem. We finally present a numerical analysis to show the performance of our methods. Results illustrate that the risk-averse joint model can effectively improve service capability and reliability than independent and risk-neutral location and inventory problems. We also recommend that the incompletely uncoordinated strategy for the joint optimisation can be more cost-effective and generate fewer workloads. Besides, the proposed algorithm achieves a more desirable performance than CPLEX for large-scale problems.
  Keywords: green closed-loop supply chain; facility location; inventory; risk-averse; chance constraint; distributionally robust optimisation.
  DOI: 10.1504/EJIE.2023.10046132
   
  
• A survey on network design problems: main variants and resolution approaches  
  by Imen Mejri, Safa Bhar Layeb, Farah Zeghal 
  Abstract: Over the last decades, network design problems (NDPs) have been one of the most investigated combinatorial optimisation problems that are still catching the interest of both practitioners and researchers. In fact, NDPs pose significant algorithmic challenges, as they are notoriously NP-hard, and arise in several applications, mainly in logistics, telecommunication, and production systems. Based on the literature published mainly between 1962 and 2021, this paper provides a comprehensive taxonomy of NDPs and also identifies the most investigated variants as well as their main fields of application. This taxonomy highlights the diversity as well as the assets of this core class of operations research problems. Moreover, the main mathematical formulations and solution methods are reported. Finally, directions for future research on NDPs are derived.
  Keywords: network design problems; NDPs; literature review; survey; combinatorial optimisation.
  DOI: 10.1504/EJIE.2022.10046171
   
  
• An auction mechanism for capacity allocation in identical parallel machines with time window constraints  
  by Qianqian Zhu, Xiuli Wang 
  Abstract: We study the scarce production capacity allocation problem in a decentralised decision-making environment. We focus on the design of an auction mechanism for effective allocation of scarce capacity, without private information. In our problem setting, the firm’s machine environment is identical parallel machines, and each customer order must be processed within a time window. Here, resource scarcity depends not only on capacity, but also on the customer orders’ time window constraints. Hence, we propose an ascending auction with a discriminatory pricing scheme for customers, to identify the real processing requirements of the customer orders and resolve resource conflicts. In our auction, the winner determination problem is NP-complete, we develop a heuristic to solve this problem using the Lagrangian relaxation technique. The computational study shows that our auction mechanism achieves over 93% of the global optimal value. [Submitted 20 April 2021; Accepted 6 May 2022]
  Keywords: capacity allocation; auction mechanism; price discrimination; Lagrangian relaxation.
  DOI: 10.1504/EJIE.2023.10050357
   
  
• Efficient Hierarchical Hybrid Delivery in the Last Mile Logistics  
  by Ardavan Babaei, Majid Khedmati, Mohammad Reza Akbari Jokar 
  Abstract: An efficient hierarchical hybrid delivery (EHHD) model is proposed by integrating a location-allocation optimisation model with a dynamic data envelopment analysis (DEA) model in this paper. The proposed model is characterised by having a periodic measurement assessing customer behaviour using the dynamic DEA, as well as developing a hierarchical connection among home delivery, the pickup point and the locker station options. The developed model considers uncertain conditions for transportation costs and customer behaviour. To solve this model, a meta-goal programming approach has been used. Based on the results of the numerical experiments, the developed model has a better performance than other competing models in terms of generating feasible and optimal solutions. Moreover, the application of the developed model is demonstrated in a case study. To the best of our knowledge, the model presented in this paper is the first attempt to simultaneously integrate customer behaviour with last-mile logistics.
  Keywords: last-mile delivery; customer behaviour data; delivery options; hierarchical; efficient; supply chain.
  DOI: 10.1504/EJIE.2023.10050962
   
  
• Decision-making and sub-coordination in a newsvendor model with a third party logistics service provider  
  by Lin Jiang, Dongmei Liu, Shuaihui Tian 
  Abstract: This paper examines the logistics strategy in a newsvendor model and considers a supply chain (SC) comprising one manufacturer, one retailer, and one third party logistics service provider (TPLSP). The retailer is responsible for transporting the products from the manufacturer to the market, and it faces a decision problem whether the product logistics functions should be outsourced to the TPLSP. Logistics outsourcing will reduce logistics cost. However, logistics outsourcing also causes classic double marginalisation because of the price of the TPLSP. Only if the TPLSP’s cost is small enough to cover double marginalisation, the logistics outsourcing can be accepted. This paper proposes a proper rule of logistics outsourcing and suggests reasonable outsourcing strategies of the retailer. Moreover, channel coordination after logistics outsourcing is discussed. Coordination schemes are often difficult to implement due to information sharing limits or administrative burden. Thus, coordination among some members of the SC, which we call sub-coordination, is easier to obtain than the coordination of all members. This paper studies two types of sub-coordination mechanisms and analyses how sub-coordination affects the newsvendor problem model with a TPLSP. [Submitted: 21 January 2022; Accepted: 31 August 2022]
  Keywords: newsvendor; logistics service provider; outsourcing; sub-coordination.
  DOI: 10.1504/EJIE.2024.10051044
   
  
• Inter-cell scheduling based on a transportation vehicle sharing strategy  
  by Qiong Liu, Qin Ye, Xu Mei, Qiang Zhang 
  Abstract: In order to quickly respond to market demands and save investments on equipment, inter-cell manufacturing with flexible routes and candidate manufacturing cells is studied. An inter-cell scheduling model aiming at minimising total costs and makespan is proposed. Current transportation strategy (CTS) for inter-cell manufacturing might cause unloaded routes of vehicles, increase transportation costs and makespan. To reduce unloaded routes, a transportation vehicle sharing strategy (TVSS) in which exceptional parts could be transported by any vehicle in a manufacturing system and vehicles do not need to be returned to their original cells without load after one transportation is proposed. An improved shuffled frog leaping algorithm (ISFLA) is designed to solve the model. A case study and several random cases are used to verify the proposed TVSS. Results show that the proposed TVSS could reduce unloaded routes effectively and yield better solutions on both total costs and makespan than the CTS. [Received: 29 March 2021; Accepted: 16 September 2022]
  Keywords: cellular manufacturing; inter-cell scheduling; multi-objective optimisation; shuffled frog leaping algorithm; SFLA; current transportation strategy; CTS; transportation vehicle sharing strategy.
  DOI: 10.1504/EJIE.2024.10051440
   
  
• Processes-oriented maturity framework for Lean Manufacturing with health-at-work and performance management objectives  
  by Gilles Galichet, Roberta COSTA AFFONSO, Vincent Cheutet 
  Abstract: Lean manufacturing is recognised as an approach that improves companies’ performance through the elimination of non-value-added activities. However, not all companies implement this approach since there is no standard method for doing so, and some authors have even identified it as a source of stress or occupational illnesses. In light of this, how can an action plan, for its implementation, be defined while guaranteeing the synergy between industrial performance and health at work? Maturity frameworks are tools that identify a company’s level of capability regarding the studied parameters, and so can serve as a guide in their organisational transformation. In this article we propose a process-oriented maturity framework for lean manufacturing transformation that considers health at work and the company’s managerial and operational performance. The framework is illustrated through a company’s evolution over the course of a five-year project, and is then discussed. [Submitted: 14 June 2021; Accepted: 19 September 2022]
  Keywords: health at work; industrial performance; maturity; organisational transformation; capability; lean manufacturing.
  DOI: 10.1504/EJIE.2024.10051586
   
  
• Service variety strategies for healthcare systems under capacity limitations  
  by Lu Chen, Yi Xia, Jiajia Zhu, Junyi Li 
  Abstract: Some hospitals provide paid medical services in addition to basic medical services. Although paid medical services can provide a better experience for patients who are highly sensitive to delays, they cause a capacity reduction in basic medical services. We develop a model incorporating product line design and queuing models to determine the service capacity allocation for a healthcare system. Patients are categorised into two segments according to their sensitivities to waiting time. We derive the optimal capacity allocations under two strategies (providing both paid and basic medical services and providing only the basic one) and compare them. Results show that the hospital should provide only the basic medical service even if high-sensitive patients are extremely sensitive to waiting time. Under certain conditions, a hospital providing differentiated medical services should decrease capacity allocation to the paid service even if high-sensitive patients are extremely sensitive to waiting time. [Submitted: 13 April 2022; Accepted: 22 September 2022]
  Keywords: healthcare system; capacity limitation; product line design; queuing model.
  DOI: 10.1504/EJIE.2024.10051678
   
  
• Two-Machine Flowshop Scheduling with Fuzzy Processing Times and Flexible Operations  
  by Zeynep Uruk, Ayten Y?lmaz Yalç?ner 
  Abstract: This paper considers a two-machine flowshop scheduling problem with fuzzy processing times and flexible operations to minimise makespan. The jobs have three operations, one of which is a flexible operation that can be processed on one of the machines. The flexible operation should be assigned to one of the machines. Moreover, the processing times on the machines are not fixed but fuzzy processing times which are assumed to have triangular possibility distributions. Firstly, a possibilistic mathematical model is proposed with fuzzy processing times and then it is converted to an auxiliary crisp model using the weighted average defuzzification method. For the large cases where the exact algorithm may not be efficient, a heuristic algorithm is proposed. [Submitted: 24 May 2022; Accepted: 18 October 2022]
  Keywords: scheduling; flowshop; makespan; fuzzy processing times; flexible operations.
  DOI: 10.1504/EJIE.2024.10052125
   
  
• Operations Research Applied to Aerospace Manufacturing and Assembly: A survey  
  by Bruno Silva, Reinaldo Morabito 
  Abstract: This paper presents an overview of operations research approaches applied to aerospace manufacturing and assembly. A survey was carried out in the main literature databases and 70 related works were found, revealing a notable growth in the number of papers in the 2010s. For the purposes of this study, aerospace industrial operations were classified into three main stages, namely manufacturing, structural and final assembly and the papers, methods and results of each stage are presented and analysed, synthesising the main applications and techniques used. Finally, a conceptual diagram of this review is presented and a synthesis of opportunities is provided for future research in this industry. [Received 31 January 2021; Accepted 19 September 2022]
  Keywords: aerospace manufacturing and assembly; survey; operations research; aerospace industry; Industry 4.0.
  DOI: 10.1504/EJIE.2024.10052262
   
  
• A Fuzzy Economic Order Quantity Model on Manufacturer-Retailer considering delay in payments: A Non-Cooperative Game Theoretical Approach  
  by DIPANJALI GHOSH, Pinki Majumder, Uttam Bera 
  Abstract: This study briefly explains the economic order quantity (EOQ) model under the fuzzy environment where a two-player non-zero-sum non-cooperative game is considered between manufacturer and retailer. Policies like trade credit are implemented and can be thought of as one type of 0% financing. Players chose to support the optimality conditions of Nash equilibrium. The main findings of the work are that under fuzzy environment, a mathematical model over profit summarisation concept has been constructed to minimise the cost of both players with the help of game theoretical approach. Different approaches have also been performed for comparative study to find out the befitting solution to the problem. The results indicate some important parameters in the present model which highly influence the optimal solution. Nonlinear optimisation technique-generalised reduced gradient (LINGO-13.0) is used to solve the problem and epitomised with some numerical data.
  Keywords: supply chain management; SCM; Nash equilibrium; FEOQ; delay in payments; ?-cut of hexagonal fuzzy number.
  DOI: 10.1504/EJIE.2024.10053031
   
  
• Temporal Aspects of Trade-offs in Organizational Performance: An Illustration from Post-disaster Debris Removal  
  by Xin Zhang, David Mendonça 
  Abstract: Trade-offs---between risk and reward, efficiency and effectiveness---are endemic to an organization's evolution and success. Until recently, however, organizational performance studies have suffered from a lack of detailed, longitudinal data, and therefore of methods that could exploit these data. While many organizations now deploy instrumentation to collect data on operations, those data are seldom directly suited to researchers' aims and are therefore characterized as `secondary'. This paper addresses this two-fold gap by casting secondary data within a theoretically grounded measurement framework and employing an innovative approach---based on Data Envelopment Analysis---to assessing the additional value provided by the data's temporal aspects. The domain of application, post-disaster debris removal, is time-constrained, potentially expensive, and crucial to post-disaster recovery. The results of this study strongly suggest the relevance of temporal aspects of the data to modeling of performance trade-offs, but also the need for further development of novel methodological approaches to examining performance trade-offs.
  Keywords: disaster response; multilevel organizations; organizational composition; organizational performance; trade-offs; secondary data; data envelopment analysis; time series; correlation analysis.
  DOI: 10.1504/EJIE.2023.10053405
   
  
• Pricing and Financing Strategies of Dual Channel Closed-loop Supply Chain Considering Capital-constrained Manufacturer  
  by Meng Xue, Di Wu, Haiqing Hu 
  Abstract: With the rise of the
  Keywords: capital-constrained; dual channel closed-loop supply chain; financing strategy; pricing strategy.
  DOI: 10.1504/EJIE.2024.10053814
   
  
• Piling and Discounting Perishable Products: Optimal Replenishment and Discounting Policy for Perishable Products  
  by Maher Agi, Xinghao Yan, Oncu Hazir 
  Abstract: Retail stores often display large quantities of perishable products that they sell at full price over a given period and then at a discount until the end of the inventory cycle. We investigate this common practice by considering a product which is subject to continuous decay through time. The demand is a function of both the price of the product and the inventory level. The retailer may discount the product once during the cycle. Closed-form expressions were provided for the maximum discounting time and cycle time. The conditions under which an optimal discount policy exists were established. The results provide insights to decision-makers on how to design a markdown policy for perishable products.
  Keywords: Inventory Management; Perishable product; Discount; Markdown Policy; inventory-level-dependent-demand.
  DOI: 10.1504/EJIE.2024.10053955
   
  
• Trust-Based Two-Stage Order Strategy of E-Commerce Platforms with Information Asymmetry  
  by Xiao Fu, Qikai Wang, Jie Li, Yan Liu, Guanghua HAN 
  Abstract: This paper explores the trust-based strategic decisions of manufacturers and e-commerce platforms. The analysis shows that the trust update model effectively supplies chain partners’ behavior. In the case of maximizing the profit of the supply chain, the manufacturer tends to recommend a higher order quantity, but due to the existence of a trust update mechanism in the e-commerce platform, the final order quantity tends to approach the actual market demand. In the case of maximizing trust, if the manufacturer blindly caters to the e-commerce platform, it deviates from the actual market demand forecast and ultimately results in losses.
  Keywords: manufacturer; e-commerce platform; trust; price discount; forecast accuracy.
  DOI: 10.1504/EJIE.2024.10054025
   
  
• Integrative Decision on New Product Development in Configurable Product Family  
  by Mazaher Ziaei, Saeedeh Ketabi, Mahsa Ghandehari 
  Abstract: Intensified competition leads companies to integrate decision-making on design, supply, and marketing policies for the new product development (NPD). This integration is more substantial for the manufacturer of the Configurable Product Family (CPF) such as cars, computers, cell phones, and home appliances. This study aims to develop a profit- maximization model to concurrent optimize all the main variables of configuration selection, components’ supply policy, price, modules’ warranty length, and launch time for NPD in CPF. To formulate the problem, it becomes necessary to develop a function to determine the potential demand of products, and a pattern for changing the demand over time, considering the mutual effects of the demand for the successive products. The proposed model is a mixed-integer nonlinear program and is solved through an adapted Differential Evolution (DE) algorithm. Different numerical cases extracted from one automobile company are studied, and sensitivity analysis on the main parameters is performed.
  Keywords: Configurable Product Family; Modules’ Warranty Length; Launch Time; Mixed-Integer Nonlinear programming; Differential Evolution (DE) Algorithm.
  DOI: 10.1504/EJIE.2024.10054465
   
  
• Penalty and Threshold Optimization of the Retailer - Vendor Return Contracts for Contract Re-Negotiation in Retail Reverse Supply Chains  
  by Mehmet Coskun, Elkafi Hassini 
  Abstract: In this paper, we consider a decentralised reverse supply chain constituting of multiple vendors and an independent retailer. The vendors offer the retailer return contracts with a multi-layered penalty structure deal. We focus on the strategic decision of developing optimal vendor re-negotiation contract parameters for the retailer. We model the problem as a mixed integer nonlinear program (MINLP) where the retailer decides on the vendor penalty fees and return thresholds simultaneously. We propose an efficient solution approach based on decomposing by decoupling the decision on penalty fees and return thresholds. The resulting problems are linear and we used them to provide rules for re-negotiation tactics for the retailer. We find that the retailer can save up to 7% from re-negotiation their contract terms. [Submitted 16 June 2022; Accepted 26 February 2023]
  Keywords: retail; reverse supply chain; decentralised decision making; coordination; vendor contracts; buyback contracts; return contracts; contract terms; product returns.
  DOI: 10.1504/EJIE.2024.10055607
   
  
• Reliable global supply chain network design under supply disruptions  
  by Changjun Wang, Mao Mao 
  Abstract: This paper studies a reliable global supply chain (GSC) design subject to uncertain supply disruptions with underlying correlation. A two-stage distributionally robust model is developed, where the joint disruption distributions are captured by an ambiguous set under a set of known marginal disruption probabilities. The proactive strategies and recourse decisions are optimised in an integrated way, the former considering the selection of suppliers, plants, and product design solutions, while the latter including multi-source procurement. We uncover the relationship between the closed-form worst-case joint distribution and the marginal disruption probabilities by proving the supermodularity of the recourse model. Therefore, the proposed min-max-min model can be equivalently reformulated as a stochastic program. Finally, an experimental study is performed. Our approach not only saves lots of costly efforts in enhancing the visibility of GSC disruptions, but also provides a promising alternative for addressing GSC design in a complex and uncertain setting.
  Keywords: global supply chain network; supply disruption; reliability; two-stage distributionally robust; supermodularity.
  DOI: 10.1504/EJIE.2024.10055919
   
  
• A Multiple Agent-Based System for the Intelligent Demand Planning of New Products  
  by Hokey Min, Wen-Bin Yu 
  Abstract: New product development (NPD) is pivotal in the firm's innovation and organic growth. Despite its strategic importance to the firm's success, it poses many managerial challenges for the effective launch of new products due to the inherent difficulty in new product demand planning. Such difficulty stems from an absence of historical sales data, shortened product life cycles, and a rapid shift in today's consumer behaviours. To deal with those demand planning challenges, this paper aims to propose a multiple agent-based system (ABS) that can overcome the shortcomings of traditional demand forecasting tools and improve forecasting accuracy significantly through the inclusion of meaningful information available from both internal and external data sources. The proposed ABS incorporates causal information obtained from four different types of agents: the coordination agent, the task agent, the data collection agent, and the interface agent. Through a series of simulation experiments, we found that the ABS improved forecasting accuracy over the traditional forecasting methods in demand planning situations where only a limited amount of historical data is available in the early introductory stages of NPD.
  Keywords: new product development; NPD; demand planning; agent-based system; ABS; simulation; business intelligence; predictive analytics.
  DOI: 10.1504/EJIE.2024.10056239
   
  
• Developing a hybrid genetic algorithm in a vehicle routing problem with simultaneous delivery and pickup and time windows: optimizing fuel consumption  
  by Nilufa Yeasmin, Sultana Parveen, Anjuman Ara 
  Abstract: The environmental deterioration due to fossil fuel burning is the significant issue in logistic industry. This issue motivates the transportation industry to improve distribution activities. The vehicle routing problem (VRP) is concerned with developing eco-distribution activities in the logistics industry. Therefore, this study considers the VRP with simultaneous delivery and pickup with time windows (VRPSDPTW), a variant of VRP and develops an environmental fuel optimisation model for VRPSDPTW to optimise the vehicle fuel consumption. This study proposes a hybrid genetic algorithm (HGA) to solve the developed fuel optimisation model and also applies GA to examine the operational efficiency of HGA. Finally, this study executes the computational experiment of two algorithms to solve the developed model under two alternate issues, i.e., fuel-oriented and distance-oriented. We found that the developed model under the fuel-oriented module reduces better fuel consumption, and the HGA performs better than GA regarding fuel consumption.
  Keywords: fuel optimisation; vehicle routing problem with simultaneous delivery and pick up and time windows; genetic algorithm; hybrid-genetic algorithm.
  DOI: 10.1504/EJIE.2024.10057051
   
  
• On designing a cumulative sum control chart using generalized Conway-Maxwell-Poisson distribution for monitoring the count data  
  by Fakhar Mustafa, Rehan Ahmad Khan Sherwani, Muhammad Ali Raza 
  Abstract: This study proposes a multipurpose cumulative-sum control chart based on the generalised Conway-Maxwell Poisson (GCOMP) distribution and names it the GCUSUM control chart. The proposed control chart monitors dispersed count data considering tail behaviour. Further, the proposed chart can also monitor zero-inflated count data. The proposed chart’s in-control and out-of-control performance analyses have been conducted using different run-length (RL) criteria. A comparative study has been presented to show the effectiveness of the proposed GCUSUM chart over established charts for monitoring distinctive features of the count data. It has been observed that the proposed control chart is efficient in monitoring the under- and over- dispersion in the count data while considering the tail behaviour. The GCUSUM chart also monitors the zero-inflated count data without utilising the zero-inflation property. Numerical and real-life examples also validate the effectiveness of the proposed control chart. [Received: 24 July 2022; accepted: 25 April 2023]
  Keywords: control chart; SPC; under-dispersion; over-dispersion; zero-inflation; tail behaviour.
  DOI: 10.1504/EJIE.2024.10057052
   
  
• A hierarchical approach to schedule the two-machine flow shop problem with flexible periodic synchronized maintenance  
  by Nahla Chabbah Sekma, Hatem Hadda 
  Abstract: This paper tackles the makespan minimisation for the well-known two-machine flow shop problem with flexible periodic maintenance activities on both machines. The maintenance starting dates are to be decided along with the job’s sequence. We adopt a hierarchical approach in which we first decide the job's sequence and then the maintenance starting dates. We identify a dominance rule and a polynomial case, and construct an enhancement procedure. We develop and test several variants of Tabu search and simulated annealing metaheuristics. We also propose an adaptation of the well-known NEH heuristic. The experimental study shows the superiority of one of the variants of simulated annealing and the efficiency of the dominance rule. [Submitted: 15 July 2022; Accepted: 8 May 2023]
  Keywords: flow shop scheduling; flexible maintenance; Tabu search; simulated annealing.
  DOI: 10.1504/EJIE.2024.10057224
   
  
• Solving the Stochastic Machine Assignment Problem with Probability-based Objectives: Problem Formulation, Solution Method, and Practical Applications  
  by Kuo-Hao Chang, Robert Cuckler 
  Abstract: In this research, a variation of the assignment problem is formulated. Diverging from many studies which model the assignment problem in a deterministic setting, this research considers a noisy and complex manufacturing process consisting of a system of workstations, each of which must be assigned a machine from a set of machine types which vary randomly according to processing time. The objective is to determine the optimal assignment solution which maximizes the probability that a production task is completed within a prespecified completion time interval; meanwhile, the traditionally-used objective, i.e., machine assignment cost, is controlled through a model constraint. The unique objective is highly useful in manufacturing applications as the reliable completion of manufacturing tasks with proper timing is crucial to avoid inventory costs or customer dissatisfaction. To solve the proposed problem, this research develops an efficient simulation optimization method which incorporates a factor screening method into a nested partitions-based framework, a powerful, globally convergent stochastic optimization algorithm. A series of numerical experiments are conducted to test the efficiency of the proposed algorithm in comparison to competing ones. Compared to existing algorithms, the proposed solution methodology was able to find feasible machine assignment solutions which generated substantially higher probabilities of job completion. [Received: 29 September 2022; Accepted: 16 February 2023]
  Keywords: Production Management; Production Planning; Simulation Applications; Simulation Optimization.
  DOI: 10.1504/EJIE.2024.10057324
   
  
• An Adaptive Large Neighborhood Search for Multi-depot Electric Vehicle Routing Problem with Time Windows  
  by Yucong Wang, Ping Chen 
  Abstract: The multi-depot electric vehicle routing problem with time windows (MDEVRPTW) is an extension of the electric vehicle routing problem with time windows (EVRPTW). Due to the driving range limit, the EVs need to recharge at some charging stations en route. In the MDEVRPTW, the EVs depart from different depots, visit the assigned customers for delivery, and finally return to the depot where they leave. The EVs could recharge at any depot or public charging station whenever necessary. This problem is formulated as a mixed-integer linear programming model, and an adaptive large neighbourhood search algorithm is proposed for solving it. In the proposed approach, both general and problem-specific destroy and repair operators are applied to improve solution quality. Numerical results show that the proposed approach can obtain high-quality solutions within less computing time and an elite version of the proposed ALNS could perform better than the complete version. [Submitted: 20 August 2021; Accepted: 25 April 2023]
  Keywords: electric vehicle routing problem; multi-depot; time windows; charging station; adaptive large neighbourhood search.
  DOI: 10.1504/EJIE.2024.10057555
   
  
• A GVNS-based approach for periodic consumables delivery to home hemodialysis patients: a case study  
  by Haifa Nouira, Adnen El Amraoui, Sondes Hammami, Gilles Goncalves, Hanen Bouchriha 
  Abstract: The use of home hemodialysis (HHD) has the potential to lower healthcare costs while improving quality-adjusted survival and quality of a patient's life. Nevertheless, the number of patients on this modality of dialysis remains low due to several barriers among which the problem of storage capacity. In fact, patients have a limited storage capacity in their homes, so they cannot store the required consumables (i.e. commodities) for long-term treatment sessions. Therefore, to promote HD use by dialysis patients, healthcare systems should offer flexible service that satisfies the patient's need in term of delivery frequency. Getting inspired by the Periodic Vehicle Routing Problem (PVRP), we develop here a mathematical formulation of the considered problem, and we propose a new approach based on the General Variable Neighborhood Search metaheuristic (GVNS) to solve it, due to its NP-hardness. To illustrate the effectiveness of the proposed approach, several tests have been performed.
  Keywords: Home dialysis Care; Periodic VRP; GVNS metaheuristic; Visit Frequency Choice; cluster-first route-second heuristic approach.
  DOI: 10.1504/EJIE.2024.10057561
   
  
• A Study on Pricing and Recycling Strategies for Retailers with Consideration of Selling New and Refurbished Products  
  by Yeu-Shiang Huang, Chih-Chiang Fang, Yi-Hsiang Tso 
  Abstract: Used products can be recycled for remanufacturing, but refurbished products may still compete with new products in a market since some price-sensitive consumers may be attracted by a low price. Therefore, firms should make price decisions for new and refurbished products with caution. This study investigates a retailer's pricing and recycling strategies for two types of consumers: quality-oriented consumers and price-sensitive consumers. The work examines internal and external competition between new and refurbished products with the consideration of consumer heterogeneity. A Stackelberg game theoretic model will be considered in the study, in which the manufacturer is a leader, who determines the official price and wholesale price first, and the retailer is a follower, who then accordingly develops optimal pricing strategies considering the two recycling policies. The analytical results show that retailers would rather recycle products on their own than outsource recycling if they were more capable of remanufacturing.
  Keywords: pricing; remanufacturing; consumer heterogeneity; game theory.
  DOI: 10.1504/EJIE.2024.10057620
   
  
• Evaluating Dispatching Rules for Make-to-Availability under Simplified Drum-Buffer-Rope: a Computational Experiment  
  by Robson Flávio Castro, Roberto Fernandes Tavares Neto, Moacir Godinho Filho 
  Abstract: This research evaluates the impact of some dispatching rules (DR) on the performance of make-to-availability (MTA) under the simplified drum-buffer-rope (S-DBR) system. S-DBR/MTA seeks to ensure the availability of finished products to meet demand, so production needs to replenish inventory quickly. The DR has an important influence on the replenishment speed, which dictates the performance of such systems. We evaluate four rules found in the literature (FIFO, AT, SPT, and SRPT), two of the S-DBR/MTA (PSP and PSP1), and six rules combining the two groups (PSP-AT, PSP-SPT, PSP PSP1-AT, PSP1-SPT, and PSP1-SRPT) using a computational experiment. We use the following measures to evaluate the performance of such rules: service level, average inventory in the system, mean flow time, and stock rate per service level percentage. The PSP1-SPT rule gets better results than others, increasing the S-DBR/MTA performance.
  Keywords: make-to-availability; MTA; simplified drum-buffer-rope; S-DBR; theory of constraint; dispatching rule; DR; flow-shop.
  DOI: 10.1504/EJIE.2024.10057827
   
  
• The Solution of Bi-Criteria Flow Shop Scheduling Problem through Mathematical Modelling and its Application in a Shoe Factory  
  by Ay?e Çelik, Serkan Kaya 
  Abstract: This paper addresses a problem occurring in a real-life shoe manufacturing factory consisting of 28 machines. Due to a large number of orders, frequent and long delays in the delivery of the products to customers occurs, which costs the factory a significant amount. The problem is formulated as a flow shop scheduling (FSS) problem and a 01 integer goal programming model is developed. Computational experiments indicate that problems with up to 50 jobs can be solved within a reasonable time by the developed model. A comparison of the results with the actual case in the factory revealed that, on the average, an improvement of 72.0% in total tardiness (TT) was achieved while an improvement of 3.9% was achieved in the maximum completion time. This helped to save the factory significantly.
  Keywords: flow shop scheduling; FSS; 0–1 integer goal programming model; shoe manufacturing; makespan; total tardiness; TT.
  DOI: 10.1504/EJIE.2024.10057892
   
  
• Hotel Overbooking, Capacity Rationing and Cooperation with Third-Parties: A Two-Period Optimization Model  
  by Nazli Karatas Aygun, Onder Bulut 
  Abstract: We propose a two-period optimisation model for a hotel revenue management (RM) problem where overbooking, capacity rationing and cooperation with third-party websites are simultaneously considered. In a Stackelberg game structure, the hotel first sets the price, and overbooking and rationing levels, and as the followers, third-parties decide their effort levels by a Nash game. The proposed model is solved using a genetic algorithm. An extensive numerical study is performed to investigate the effects of multiple night stays, hotel effort level, and hotel capacity on the decisions and the hotel profit. It is shown that the value of capacity rationing increases with multiple night stays and the expected profit of the third-parties is decreasing with the hotel effort level but the relation between the hotel effort level and profit is not monotone. As the hotel capacity is expanded, the effort level of the third-parties and the hotel profit increase. [Submitted: 1 December 2021; Accepted: 26 May 2023]
  Keywords: pricing; overbooking; third-party websites; multiple night stays; multiple customer classes; two-period optimisation model.
  DOI: 10.1504/EJIE.2024.10058072
   
  
• The influence of shelf life on the integrated production scheduling and vehicle routing optimization for perishable products  
  by Hercules Tadeu Asato Dantas, Roberto Fernandes Tavares Neto, Juliana K. Sagawa 
  Abstract: Prior studies on integrating production and distribution optimisation highlight the benefits of such an approach. However, no studies regarding standardised metrics for categorising shelf life lengths in different scenarios were found. Moreover, the current literature does not address the change of behaviour on solving strategies accordingly to different shelf life profiles. To address these gaps, this research proposes the normalised shelf life metric to classify long and short shelf life products. Additionally, we present a simplified optimisation formulation for the integrated production scheduling and vehicle routing problem. By evaluating three solution methods (MILP model, genetic algorithm, and logic-based Benders decomposition model), our findings reveal that shelf life significantly affects solution performance. These results emphasise the need for research focused on solution methods tailored specifically for short shelf life products. [Submitted: 26 July 2022; Accepted: 7 June 2023]
  Keywords: shelf life; production-distribution integration; perishable products; genetic algorithm.
  DOI: 10.1504/EJIE.2024.10058090
   
  
• Robust supplier selection under uncertain costs and delivery delay times  
  by Cassiano Tavares, Pedro Munari, Moacir Godinho Filho 
  Abstract: We address the supplier selection problem under uncertainty, motivated by the current economic situation of global trade. The intense search among organisations for responsiveness in meeting market demands has directed efforts toward supply chain optimisation. Consequently, the decision regarding the best supplier choice has become vital for the success of organisations, requiring a high level of accuracy and assertiveness under complex and uncertain environments. To support decision-making in global sourcing environments, we propose a robust optimisation model that incorporates cost and time uncertainties that commonly arise in the context of worldwide raw materials supply. The model includes raw materials inventory management, preventing stockouts and violations of physical storage constraints, while considering deviations of the uncertain parameters. We analyse the behaviour of the proposed model using 324,000 scenarios generated by Monte Carlo simulations. The results show that the proposed model increases the level of robustness without significantly increasing the value of the objective function when uncertain costs and times attain their worst-case scenarios (highest deviation). On average, the objective function values increased only 3.58% in the worst case, considering 20 products, 40 periods, 60 suppliers, and an uncertainty level of 50%. [Submitted: 1 June 2022; Accepted: 10 May 2023]
  Keywords: supplier selection; uncertainty; inventory; VUCA; robust optimisation.
  DOI: 10.1504/EJIE.2024.10058218
   
  
• Multi-objective University Rescheduling Problem by Fuzzy Programming Technique  
  by Sunil Bhoi, Jayesh Dhodiya 
  Abstract: This study presents multi-objective university rescheduling assignment problem (MOURAP), when some faculty members have been left the institute due to unavoidable circumstances, i.e., disruptions. This presented model executed in two phases. The first phase discuss and formulate the university course rescheduling problem and allocate all unassigned courses to available faculty members based on preferences for course of faculty members, administrator and indirect students preferences computed on faculty feedback and student result analysis. In second phase, pair of faculty member and course assigned to time slots based on faculty member preferences. The prime aim of rescheduling is to minimise the course allocation change from former and latter to faculty members and time slots allocations change from initial and new schedule to faculty members and students. To test the strength of presented model, this study demonstrated the model with two numerical examples on hypothetical data. With hypothetical numerical data, model has been executed and generated new schedule by fuzzy programming technique wit linear and exponential membership functions. This technique always produced non-dominated/compromise solutions. Results are obtained using LINGO19.0 software. [Submitted: 14 January 2022; Accepted: 9 July 2023]
  Keywords: university scheduling; rescheduling; 0-1 integer programming; fuzzy programming technique.
  DOI: 10.1504/EJIE.2024.10058383
   
  
• A bi-objective MILP model for an open-shop scheduling problem with reverse flows and sequence-dependent setup times  
  by Saba Aghighi, Esmaeil Mehdizadeh, Seyed Taghi Akhavan Niaki, Amir Abbas Najafi 
  Abstract: In this research, the scheduling problem of open-shop scheduling problem (OSSP) with sequence-dependent setup time (SDST) is investigated considering the reverse flow (assemble/disassemble flow on the same machines). The problem is formulated as a bi-objective mixed-integer linear programming (MILP) model. It involves reverse flows to minimise the completion time (Cmax) and total tardiness. Since the OSSP is an NP-hard problem, a vibration damping-based multi-objective optimisation algorithm (MOVDO) is employed to solve large test problems in a reasonable runtime. Analysing the results of this algorithm was compared to an Epsilon-constrained method, which produced similar results in small problem sizes. Additionally, this algorithm is compared to other multi-objective algorithms, such as MOACO, MO-Cuckoo search, and NSGA-II, in terms of its performance. Based on the performance of these algorithms, we show that the proposed MOVDO algorithm performs better than the other algorithms to solve this problem. Eventually, a case study is investigated to validate the mathematical model and demonstrate the application. Comparing the proposed model to the results in the real world, the proposed model shows an improvement.
  Keywords: open-shop scheduling problem; OSSP; reverse flows; sequence-dependent setup times; SDST; vibration damping-based optimisation algorithm; MOVDO.
  DOI: 10.1504/EJIE.2024.10059187
   
  
• Compact MILP Models for Double Row Layout Problem with Pairwise Clearance
  by Richard Alaimo, Churlzu Lim 
  Abstract: Double row layout problem (DRLP) seeks for an optimal arrangement of departments along both sides of a central corridor to minimise the total material flow cost. This study considers a variant of DRLP where pairwise minimum clearance requirements between departments are enforced when they are assigned to the same side. This problem accounts for additional interaction that exists between departments during the layout planning process. Two mixed-integer linear programming formulations are proposed with the motivation that using fewer binary variables compared to the existing formulation in the literature helps reduce the solution time. Noting the NP-hardness of the problem, symmetry-breaking constraints are investigated in an effort to further alleviate the computational burden. The efficacy of the proposed models is demonstrated via a computational study using a set of test problem instances. [Submitted: 9 February 2022; Accepted: 11 August 2023]
  Keywords: facility layout; double row layout problem; mixed-integer linear programming; combinatorial optimisation; clearance requirements.