Article
Operations Research & Management Science
Junyuan Wang, Jimin Ye, Liang Wang
Summary: In this paper, extended preventive replacement models for series and parallel system with n independent non-identical components are proposed. The models consider two types of failure and offer different options for replacement. The average cost rate function and failure rate function under different cases are obtained. The optimal preventive replacement time based on minimizing the average cost rate function is also determined. Numerical examples are provided for cost evaluation and performance verification.
ANNALS OF OPERATIONS RESEARCH
(2022)
Article
Mathematics
Radim Bris, Pavel Jahoda
Summary: The study considers complex systems with both preventive and corrective maintenance. By examining the mathematics of reliability, a failure-based preventive maintenance model is proposed to address the issue of increased unavailability due to imperfect corrective maintenance. A new method for finding an optimal failure-based preventive maintenance policy is described in the paper, which aims to meet a given reliability constraint.
Article
Engineering, Industrial
Minjae Park, Hoang Pham
Summary: This paper proposes a condition-based maintenance strategy for a degradation-shock dependence system. The paper develops a reliability model and conducts a warranty cost analysis to optimize the warranty strategy. The study considers the dependence between degradation and random shocks and investigates different types of shocks and their effects on system degradation.
INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH
(2023)
Article
Engineering, Multidisciplinary
Liying Jiang, Bo Li, Jiawen Hu
Summary: Age-based preventive replacement policy focuses on finding the optimal combination of minimal repair, corrective replacement, and imperfect repair to minimize long-term average maintenance cost.
QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL
(2023)
Article
Operations Research & Management Science
Sergey S. Ketkov, Oleg A. Prokopyev, Lisa M. Maillart
Summary: This paper investigates a system that generates rewards with a decreasing rate as its virtual age increases. Periodic maintenance is performed to restore the system and decrease its lifetime. The study formulates a repair-replacement problem and proposes global optimization techniques and analytical observations. The findings are particularly important for battery-powered remote monitoring systems.
ANNALS OF OPERATIONS RESEARCH
(2023)
Article
Engineering, Industrial
Qin Zhang, Zhigeng Fang, Jiajia Cai
Summary: For mission-oriented systems, it is important to propose appropriate preventive maintenance policies to ensure system reliability and maintainability. Traditional replacement policies may lead to overestimation of planned missions and increased system failure risk during missions.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2021)
Article
Management
Chin-Chih Changa
Summary: This paper proposes a decision model to determine the optimal renewing free-maintenance warranty (RFMW) period and preventive replacement age for a general repairable product with a random workload. The effects of RFMW on the optimal preventive replacement model are further investigated through comparative studies and a numerical example, demonstrating the model's generalized application in maintenance theory and warranty strategy.
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY
(2022)
Article
Engineering, Multidisciplinary
Yen-Luan Chen, Chin-Chih Chang, Zhe George Zhang, Xiaofeng Chen
Summary: This paper introduces modified preventive maintenance policies for an operating system that operates at random processing times and is imperfectly maintained. The system may experience two types of failures based on a time-dependent imperfect maintenance mechanism. Two maintenance policies, preventive maintenance-first (PMF) and preventive maintenance-last (PML), are applied to the system, with the optimal preventive maintenance schedule derived and determined analytically and numerically. The proposed models offer a general framework for analyzing maintenance policies in reliability theory.
JOURNAL OF INDUSTRIAL AND MANAGEMENT OPTIMIZATION
(2021)
Article
Computer Science, Hardware & Architecture
Rui Zheng, Xiaofei Qian, Liudong Gu
Summary: This article presents a framework to derive the optimal group maintenance policy for an NC machine tool comprised of heterogeneous components from real failure histories. The framework includes a criticality analysis to identify high-risk and low-risk components, as well as a multilevel PM decision-making approach at the component and system levels. The proposed approach is illustrated using the failure histories of an NC machine tool with 13 components.
IEEE TRANSACTIONS ON RELIABILITY
(2023)
Review
Cell Biology
Mansour Akbari, Hilde Loge Nilsen, Nicola Pietro Montaldo
Summary: Mitochondria are essential for cellular energy production and play a crucial role in organismal development and normal function. Understanding the mechanisms of mtDNA maintenance and transcription can provide insights into the pathogenesis of various diseases.
FRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY
(2022)
Article
Management
Peng Liu, Guanjun Wang
Summary: Nowadays, many warranted products are sold with repair thresholds to protect customer interests. We study a non-renewing replacement warranty policy that considers a repair number threshold and repair time threshold. The manufacturer replaces a product if the number of failures exceeds the repair number threshold or the cumulative repair time reaches the repair time threshold. We also develop an age-based post-warranty maintenance strategy, which offers a lower cost rate compared to existing strategies. Through numerical experiments, we analyze the effects of various parameters on the proposed maintenance strategy.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2023)
Article
Mathematics
Mingjuan Sun, Qinglai Dong, Zihan Gao
Summary: Based on the extended geometric process, this study investigates a repair replacement model of a degradation system, in which the delayed repair time depends on the working time after the last repair. The study focuses on two replacement policies and obtains the exact expressions of the long-run average cost rate. Numerical examples are provided to demonstrate the application of the results obtained in the study.
Article
Computer Science, Interdisciplinary Applications
Shey-Huei Sheu, Tzu-Hsin Liu, Zhe-George Zhang, Xufeng Zhao, Yu-Hung Chien
Summary: This paper discusses two extended preventive replacement models for systems that execute projects at random times. The system is subject to shocks and experiences two types of failures with probabilities depending on age. The long-run expected cost rate for each replacement policy is analyzed, and the optimum preventive replacement policy is determined analytically. The paper also shows that several previous replacement models in the literature are special cases of these two models.
COMPUTERS & INDUSTRIAL ENGINEERING
(2021)
Article
Engineering, Industrial
Satoshi Mizutani, Xufeng Zhao, Toshio Nakagawa
Summary: This paper examines age and periodic replacement policies in general replacement models, considering major and minor failures. The expected cost rates for planned replacement policies are calculated and optimal regular and random replacement policies are compared analytically in terms of cost. Numerical analyses illustrate exponential minor failure, exponential major failure, and Weibull major failure with increasing hazard rate of minor failure.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2021)
Article
Engineering, Industrial
Chin-Chih Chang, Yen-Luan Chen
Summary: This paper investigates an ordering-replacement modelling framework for a system deteriorating with repairable and unrepairable failures. The objective is to optimize system availability, expected cost rate, and cost-effectiveness by finding the optimal spare unit ordering schedule. The existence and uniqueness of each optimal ordering policy are derived analytically and computed numerically.
INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE-OPERATIONS & LOGISTICS
(2023)
Article
Management
Phil Scarf, Rishikesh Parma, Ian McHale
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2019)
Article
Engineering, Industrial
Phuc Do, Roy Assaf, Phil Scarf, Benoit Iung
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2019)
Article
Engineering, Industrial
Ibrahim Nafisah, Mansour Shrahili, Naif Alotaibi, Phil Scarf
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2019)
Article
Computer Science, Hardware & Architecture
Cristiano A. V. Cavalcante, Philip A. Scarf, M. D. Berrade
IEEE TRANSACTIONS ON RELIABILITY
(2019)
Article
Management
P. A. Scarf, C. A. Cavalcante, R. S. Lopes
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2019)
Editorial Material
Management
Rogemar Mamon, Phil Scarf, Aris Syntetos
IMA JOURNAL OF MANAGEMENT MATHEMATICS
(2020)
Article
Management
N. M. Alotaibi, C. A. Cavalcante, R. S. Lopes, P. A. Scarf
IMA JOURNAL OF MANAGEMENT MATHEMATICS
(2020)
Article
Engineering, Industrial
Cristiano A. Cavalcante, Rodrigo S. Lopes, Philip A. Scarf
Summary: The study focuses on an inspection and replacement policy for systems, emphasizing what maintenance to schedule at known times rather than when to schedule maintenance. The model considers limitations in time and resources that may lead to violations. Results show that the scheduled time for preventive replacement and the effective visit-frequency have the largest effect on policy performance.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2021)
Article
Management
Rose Bake, Simon Chadwick, Rishikesh Parma, Phil Scarf
Summary: The study introduces the binomial-match model as a challenger to the Poisson-match, primarily for studying the relationship between outcome uncertainty and scoring-rate in sports competitions. The binomial-match is not a better forecaster than the Poisson-match, but it is better for representing outcome uncertainty and evaluating rule-variations and tactics, particularly in the context of netball.
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY
(2022)
Article
Management
Aaditya Singh, Phil Scarf, Rose Baker
Summary: This study presents three fundamental models for modelling the bivariate scores in possessive ball-sports. These models can be used for prediction, experimentation, and explanation. The Markov-match model is a new model that complements the binomial-match model. The Markov-match model induces a larger correlation between the scores of competitors but slightly more tied outcomes.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2023)
Article
Engineering, Multidisciplinary
Yan R. Melo, Cristiano A. Cavalcante, Phil Scarf, Rodrigo S. Lopes
Summary: This study proposes a maintenance policy for remote systems that combines periodic inspection and opportunistic replacement. The results indicate that opportunistic replacement can significantly impact the cost-rate of the optimum policy but cannot achieve very high availability. Therefore, maintenance planning should be flexible when external factors influence maintenance effectiveness.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART O-JOURNAL OF RISK AND RELIABILITY
(2023)
Article
Management
Phil Scarf, Aris Syntetos, Ruud Teunter
Summary: This paper calls for further integration between spare-parts inventory planning and maintenance, reviewing literature on mathematical modelling and analysis of inventory-maintenance planning. It also discusses simple stock keeping rules for joint planning of inventory and maintenance. The work aims to bridge the gap between theory and practice and is relevant for both researchers and practitioners.
IMA JOURNAL OF MANAGEMENT MATHEMATICS
(2023)
Article
Engineering, Industrial
Naif M. Alotaibi, Philip Scarf, Cristiano A. V. Cavalcante, Rodrigo S. Lopes, Andre Luiz de Oliveira e Silva, Augusto J. S. Rodrigues, Salem A. Alyami
Summary: This study presents a maintenance policy model that combines opportunistic and scheduled inspections. The inspections are randomly determined, with the system only being checked if it has reached a certain age. In addition, emergency inspections are carried out once the system reaches a specific age. The model considers the flexibility of inspections based on production, missions, and convenience, while still adhering to statutory and safety regulations. The model's outcomes were analyzed numerically to assess the cost-rate and mean time between operational failures for different parameter values. The model proves useful in quantifying the advantages and disadvantages of flexible inspection policies and demonstrates that better utilization of inspection opportunities can lead to cost reduction and increased reliability.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2023)
Article
Hospitality, Leisure, Sport & Tourism
William Gerard Ryan, Alex Fenton, Wasim Ahmed, Phillip Scarf
INTERNATIONAL JOURNAL OF EVENT AND FESTIVAL MANAGEMENT
(2020)
Review
Management
Vinicius N. Motta, Miguel F. Anjos, Michel Gendreau
Summary: This survey presents a review of optimization approaches for the integration of demand response in power systems planning and highlights important future research directions.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Philipp Schulze, Armin Scholl, Rico Walter
Summary: This paper proposes an improved branch-and-bound algorithm, R-SALSA, for solving the simple assembly line balancing problem, which performs well in balancing workloads and providing initial solutions.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Roshan Mahes, Michel Mandjes, Marko Boon, Peter Taylor
Summary: This paper discusses appointment scheduling and presents a phase-type-based approach to handle variations in service times. Numerical experiments with dynamic scheduling demonstrate the benefits of rescheduling.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Oleg S. Pianykh, Sebastian Perez, Chengzhao Richard Zhang
Summary: Efficient scheduling is crucial for optimizing resource allocation and system performance. This study focuses on critical utilization and efficient scheduling in discrete scheduling systems, and compares the results with classical queueing theory.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Review
Management
Hamed Jahani, Babak Abbasi, Jiuh-Biing Sheu, Walid Klibi
Summary: Supply chain network design is a large and growing area of research. This study comprehensively surveys and analyzes articles published from 2008 to 2021 to detect and report financial perspectives in SCND models. The study also identifies research gaps and offers future research directions.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Patrick Healy, Nicolas Jozefowiez, Pierre Laroche, Franc Marchetti, Sebastien Martin, Zsuzsanna Roka
Summary: The Connected Max-k-Cut Problem is an extension of the well-known Max-Cut Problem, where the objective is to partition a graph into k connected subgraphs by maximizing the cost of inter-partition edges. The researchers propose a new integer linear program and a branch-and-cut algorithm for this problem, and also use graph isomorphism to structure the instances and facilitate their resolution. Extensive computational experiments show that, if k > 2, their approach outperforms existing algorithms in terms of quality.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Victor J. Espana, Juan Aparicio, Xavier Barber, Miriam Esteve
Summary: This paper introduces a new methodology based on the machine learning technique MARS for estimating production functions that satisfy classical production theory axioms. The new approach overcomes the overfitting problem of DEA through generalized cross-validation and demonstrates better performance in reducing mean squared error and bias compared to DEA and C2NLS methods.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Stefano Nasini, Rabia Nessah
Summary: In this paper, the authors investigate the impact of time flexibility in job scheduling, showing that it can significantly affect operators' ability to solve the problem efficiently. They propose a new methodology based on convex quadratic programming approaches that allows for optimal solutions in large-scale instances.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Zhiqiang Liao, Sheng Dai, Timo Kuosmanen
Summary: Nonparametric regression subject to convexity or concavity constraints is gaining popularity in various fields. The conventional convex regression method often suffers from overfitting and outliers. This paper proposes the convex support vector regression method to address these issues and demonstrates its advantages in prediction accuracy and robustness through numerical experiments.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Kuo-Hao Chang, Ying-Zheng Wu, Wen-Ray Su, Lee-Yaw Lin
Summary: The damage and destruction caused by earthquakes necessitates the evacuation of affected populations. Simulation models, such as the Stochastic Pedestrian Cell Transmission Model (SPCTM), can be utilized to enhance disaster and evacuation management. The analysis of SPCTM provides insights for government officials to formulate effective evacuation strategies.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Qinghua Wu, Mu He, Jin-Kao Hao, Yongliang Lu
Summary: This paper studies a variant of the orienteering problem known as the clustered orienteering problem. In this problem, customers are grouped into clusters and a profit is associated with each cluster, collected only when all customers in the cluster are served. The proposed evolutionary algorithm, incorporating a backbone-based crossover operator and a destroy-and-repair mutation operator, outperforms existing algorithms on benchmark instances and sets new records on some instances. It also demonstrates scalability on large instances and has shown superiority over three state-of-the-art COP algorithms. The algorithm is also successfully applied to a dynamic version of the COP considering stochastic travel time.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Bjorn Bokelmann, Stefan Lessmann
Summary: Estimating treatment effects is an important task for data analysts, and uplift models provide support for efficient allocation of treatments. However, evaluating uplift models is challenging due to variance issues. This paper theoretically analyzes the variance of uplift evaluation metrics, proposes variance reduction methods based on statistical adjustment, and demonstrates their benefits on simulated and real-world data.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Congzheng Liu, Wenqi Zhu
Summary: This paper proposes a feature-based non-parametric approach to minimizing the conditional value-at-risk in the newsvendor problem. The method is able to handle both linear and nonlinear profits without prior knowledge of the demand distribution. Results from numerical and real-life experiments demonstrate the robustness and effectiveness of the approach.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Laszlo Csato
Summary: This paper compares the performance of the eigenvalue method and the row geometric mean as two weighting procedures. Through numerical experiments, it is found that the priorities derived from the two eigenvectors in the eigenvalue method do not always agree, while the row geometric mean serves as a compromise between them.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
Article
Management
Guowei Dou, Tsan-Ming Choi
Summary: This study investigates the impact of channel relationships between manufacturers on government policies and explores the effectiveness of positive incentives versus taxes in increasing social welfare. The findings suggest that competition may be more effective in improving sustainability and social welfare. Additionally, government incentives for green technology may not necessarily enhance sustainability.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2024)
