Template-Type: ReDIF-Article 1.0 Author-Name: Xiuzhu Gu Author-X-Name-First: Xiuzhu Author-X-Name-Last: Gu Author-Name: Mingming Deng Author-X-Name-First: Mingming Author-X-Name-Last: Deng Title: Disclosing harmful patient safety incidents with proactive compensation offer: how do patients respond in Japan? Abstract: Disclosure of harmful incidents is important as patients have the right to know the truth. This study aims to explore the impacts of <em>partial</em> and <em>full</em> disclosure, alongside proactive compensation offers on Japanese patients' reactions. A questionnaire survey was conducted using two fictitious cases with four types of disclosure scenarios. Participants were asked inquired about the actions they would be inclined to take if they were the ones affected. A total of 543 responses to the moderate and 587 responses to the severe harm case were collected. The findings in this study suggest that similar reactions were observed from Japanese patients after receiving full or partial disclosure. In addition, proactive compensation offers had a mitigation effect on patient complaints complains and lawsuits. Therefore, for Japanese healthcare providers, such evidence could relieve their fear of patients' reactions after full disclosure; and for healthcare organisations, it is recommended that proactive compensation offers be included alongside disclosure programs. Journal: Int. J. of Reliability and Safety Pages: 321-336 Issue: 4 Volume: 18 Year: 2024 Keywords: patient safety incident; patient harm; partial disclosure; full disclosure; compensation; patient reaction. File-URL: http://www.inderscience.com/link.php?id=142086 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:4:p:321-336 Template-Type: ReDIF-Article 1.0 Author-Name: Xiuqing Yang Author-X-Name-First: Xiuqing Author-X-Name-Last: Yang Author-Name: Xiaorui Wang Author-X-Name-First: Xiaorui Author-X-Name-Last: Wang Author-Name: Dongfei Zhao Author-X-Name-First: Dongfei Author-X-Name-Last: Zhao Author-Name: Wei He Author-X-Name-First: Wei Author-X-Name-Last: He Author-Name: Ting Li Author-X-Name-First: Ting Author-X-Name-Last: Li Title: Evaluating reliability in airport baggage handling: a time-based assessment of the individual carrier system Abstract: The Individual Carrier System (ICS) represents a critical component in airport baggage handling, necessitating rigorous reliability assessments during both its developmental and operational stages. This research introduces an innovative methodology for ICS reliability evaluation centred on baggage transport time. Here, transport time is articulated as an amalgamation of ideal transport time and sequential queuing durations. Building on these foundational models, we have devised a reliability simulation framework that assimilates both deterministic system parameters and stochastic input variables. This integrative approach facilitates the determination of pertinent reliability indices and associated failure probabilities. To underscore the practical implications and robustness of our methodology, we delve into a real-world ICS test system. Our findings illuminate the nuanced interplay between average pallet wait times and total pallet input numbers. Furthermore, we chart the trajectory of the reliability index in relation to initial loading intensities. Such insights bear significant ramifications for both the architectural design of ICS and their operational efficiency within airport environments. Journal: Int. J. of Reliability and Safety Pages: 363-380 Issue: 4 Volume: 18 Year: 2024 Keywords: logistics engineering; real-time reliability assessment; tandem queuing model; ICS; individual carrier system; transportation time. File-URL: http://www.inderscience.com/link.php?id=142090 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:4:p:363-380 Template-Type: ReDIF-Article 1.0 Author-Name: Vasilis P. Koutras Author-X-Name-First: Vasilis P. Author-X-Name-Last: Koutras Author-Name: Sonia Malefaki Author-X-Name-First: Sonia Author-X-Name-Last: Malefaki Title: Modelling opportunistic maintenance and its effects on the dependability and performance of k-out-of-n systems Abstract: A wide range of production, manufacturing, industrial and general technological systems reveal a <em>k</em>-out-of-<em>n</em> structure. A <em>k</em>-out-of-<em>n</em> system is considered as operational when at least <em>k</em> of the <em>n</em> components are operational. Owing to this, upon a planned or an unplanned stoppage of a component and given that the remaining operating components are equal to or more than <em>k</em>, an opportunity to preventively maintain degraded components arises. Such an action, called Opportunistic Maintenance (OM), aims to improve the condition of the entire <em>k</em>-out-of-<em>n</em> system after the completion of all required restoration actions. In the current work, a new state-based approach is introduced to model OM for <em>k</em>-out-of-<em>n</em> multi-state systems. Based on the proposed model, the effects of OM on <em>k</em>-out-of-<em>n</em> multi-state systems' dependability and performance are extensively studied. The paper provides the appropriate theoretical framework for modelling OM and its effects on transient as well as on asymptotic availability and total expected operational cost. Moreover, through numerical examples, it is obtained that OM manages to provide practically the same availability with the systems without any OM action, but significantly lower operational cost. Thus, this work provides a cost-effective and easy to implement approach for enabling OM on <em>k</em>-out-of-<em>n</em> systems. Journal: Int. J. of Reliability and Safety Pages: 337-362 Issue: 4 Volume: 18 Year: 2024 Keywords: opportunistic maintenance; k-out-of-n systems; multi-state systems; availability; operational cost; Markov process. File-URL: http://www.inderscience.com/link.php?id=142092 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:4:p:337-362 Template-Type: ReDIF-Article 1.0 Author-Name: Saurabh Jaglan Author-X-Name-First: Saurabh Author-X-Name-Last: Jaglan Author-Name: Praveen Aggarwal Author-X-Name-First: Praveen Author-X-Name-Last: Aggarwal Author-Name: Sunita Kumari Author-X-Name-First: Sunita Author-X-Name-Last: Kumari Title: A comparative study of M5P, ANN and RENB models for prediction of vulnerable road accident frequency Abstract: The present investigation aims to evaluate the performance of different models to calculate the Vulnerable Road User Accident Frequency (VRUAF). Nine road stretches were chosen to measure the road geometry and other similar characteristics. Many field studies were conducted to gather information about road geometry, traffic surveys and accident characteristics. A total of 17 input parameters were collected for accident frequency analysis, and three prediction approaches were applied: Fixed/Random Effect Negative Binomial (FENB/RENB) regression models, Artificial Neural Network (ANN) and M5P model tree. The variation in models' performance was observed in terms of the coefficient of correlation (0.943-0.981), root mean square error (2.274-1.655) and mean absolute error (1.746-1.351). The result suggests that the ANN model is the most accurate model where CC, MAE and RMSE values are 0.981, 1.351 and 1.655, respectively. Thus, this model can synthetically predict VRUAF under similar geometric conditions. Journal: Int. J. of Reliability and Safety Pages: 231-251 Issue: 3 Volume: 18 Year: 2024 Keywords: vulnerable road user; accident frequency; artificial neural network; random effect negative binomial model; M5P model tree. File-URL: http://www.inderscience.com/link.php?id=140610 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:3:p:231-251 Template-Type: ReDIF-Article 1.0 Author-Name: Bouba Oumarou Aboubakar Author-X-Name-First: Bouba Oumarou Author-X-Name-Last: Aboubakar Author-Name: HongXia Li Author-X-Name-First: HongXia Author-X-Name-Last: Li Title: Influence of safety culture on Chinese overseas hydropower project workers' safety performance: a case study in Cameroon Abstract: This paper evaluates the influence of safety culture on the safety performance of Chinese hydropower projects in Cameroon. It addresses the intrinsic influence of external hazards management, national culture, workers' safety knowledge and attitudes, Chinese managers' commitment on safety behaviours and motivation of 566 workers using a structural model analysed by Lisrel. The results revealed that (1) external hazards management positively influences safety motivation of both Chinese and local workers, but does not have a significant influence on their safety behaviours; (2) national culture sharing positively influences safety behaviours and safety motivation of workers; (3) workers' safety knowledge slightly influences safety behaviour but not their safety motivation; (4) safety attitude positively influences safety behaviours; (5) safety commitment of Chinese management leads to positive safety behaviour and safety motivation of workers. Finally, theoretical and practical implications are proposed and suggestions for future work are also given based on the results in this study. Journal: Int. J. of Reliability and Safety Pages: 266-301 Issue: 3 Volume: 18 Year: 2024 Keywords: safety culture; safety performance; hydropower projects; structural equation modelling; Chinese contractors. File-URL: http://www.inderscience.com/link.php?id=140614 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:3:p:266-301 Template-Type: ReDIF-Article 1.0 Author-Name: J. Madhumitha Author-X-Name-First: J. Author-X-Name-Last: Madhumitha Author-Name: G. Vijayalakshmi Author-X-Name-First: G. Author-X-Name-Last: Vijayalakshmi Title: Reliability analysis of three state linear consecutive 2-out-of-4:F system by continuous time Markov model Abstract: In this paper, the continuous time Markov model for the L (cons/2-4:F) system is described. Each component of the system has three states (good state, degraded state and failed state). The failure and repair times follow an exponential distribution. The dependability measures such as availability and reliability are obtained. The effects of failure and repair rates on system availability and system reliability are presented. The mathematical consequences of the reliability measures will be of incredible assistance to the system engineers and decision-makers in improving and designing the system in future. The proposed system can be used in nuclear power plants and telecommunication systems. Journal: Int. J. of Reliability and Safety Pages: 252-265 Issue: 3 Volume: 18 Year: 2024 Keywords: linear consecutive 2-out-of-4:F system; continuous time Markov model; multi-state system; reliability; availability. File-URL: http://www.inderscience.com/link.php?id=140616 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:3:p:252-265 Template-Type: ReDIF-Article 1.0 Author-Name: Vinod V. Nair Author-X-Name-First: Vinod V. Author-X-Name-Last: Nair Author-Name: Sindhura Rose Thomas Author-X-Name-First: Sindhura Rose Author-X-Name-Last: Thomas Author-Name: Usha Nair Author-X-Name-First: Usha Author-X-Name-Last: Nair Title: Reliability assessment of electricity distribution networks based on nodal power flow adequacy and voltage levels Abstract: A novel method for reliability assessment covering generation adequacy and voltage stability of electric distribution networks is developed from the power flow equations. A Power Dependent Voltage Stability Index (PDVSI) is shown to be a generation adequacy measure for baseline operating voltage of a network. The PDVSI values and the differential change in PDVSI characterise the power flow adequacy level of nodes in electric distribution networks. The PDVSI method is applied to multiple configurations of a three-node system with generation and consumption nodes to show the applicability in the presence of distributed generation. Rapid assessment of reliability levels using PDVSI methodology in combination with <em>K</em>-Means clustering method is demonstrated to automate the classification of the operating points as stable and unstable. Application to the modified IEEE 69 bus test system illustrates that it can be used in real world electric distribution network systems. Journal: Int. J. of Reliability and Safety Pages: 302-320 Issue: 3 Volume: 18 Year: 2024 Keywords: clustering; electric distribution networks; power flow; reliability assessment; voltage stability. File-URL: http://www.inderscience.com/link.php?id=140622 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:3:p:302-320 Template-Type: ReDIF-Article 1.0 Author-Name: Intekhab Alam Author-X-Name-First: Intekhab Author-X-Name-Last: Alam Author-Name: Mustafa Kamal Author-X-Name-First: Mustafa Author-X-Name-Last: Kamal Author-Name: Ahmadur Rahman Author-X-Name-First: Ahmadur Author-X-Name-Last: Rahman Author-Name: Nayabuddin Author-X-Name-First: Author-X-Name-Last: Nayabuddin Title: A study on step stress partially accelerated life test under adaptive type-II progressive hybrid censoring for inverse Lomax distribution Abstract: Using traditional life tests in testing and reliability theory may result in extremely few failures by the completion of the experiment, leading to poorer estimations. To get the required failure as rapidly as possible for better estimation, products are exposed to higher stress levels, and this process is known as accelerated life testing. This paper develops a step stress partially accelerated life test that employs adaptive type-II progressive hybrid censoring scheme and assumes that the lifespan of test items follows a two-parameter inverted Lomax distribution. The likelihood and log-likelihood functions were created for adaptive type-II progressive hybrid censoring scheme data in order to get the point and interval of the model parameters using the maximum-likelihood estimation approach. Furthermore, using a Monte Carlo simulation analysis, the biases and mean square errors of the maximum-likelihood estimators are estimated to examine their performances in the presence of censoring introduced in this work. Journal: Int. J. of Reliability and Safety Pages: 1-18 Issue: 1 Volume: 18 Year: 2024 Keywords: partially accelerated life test; inverse Lomax distribution; Newton Raphson; adaptive type-II progressive hybrid censoring; simulation study. File-URL: http://www.inderscience.com/link.php?id=139194 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:1:p:1-18 Template-Type: ReDIF-Article 1.0 Author-Name: Najmadeen Mohammed Saeed Author-X-Name-First: Najmadeen Mohammed Author-X-Name-Last: Saeed Title: Recent advances in structural health monitoring: techniques, applications and future directions Abstract: Structural Health Monitoring (SHM) ensures structure safety, reliability, and durability in many sectors. SHM methods have improved structural evaluation and maintenance efficiency to meet sustainable infrastructure and lower maintenance expenses. This article discusses current SHM achievements, their benefits, and future research in this rapidly growing field. Basic SHM procedures start with manual monitoring and visual inspections. Advanced sensors, data analytics and machine learning algorithms have transformed SHM. Industrial, aerospace, energy and civil infrastructure use SHM. SHM optimises processes and quality control, improving product reliability and waste reduction. It covers smart materials, low-cost, lightweight, energy-efficient sensor technologies and advanced data analytics for better decision-making. Advanced sensors, data analytics and machine learning algorithms enable real-time monitoring, anomaly detection and preventative maintenance using SHM. Advanced sensor technologies and SHM integration with cutting-edge technology will shape this industry and improve SHM and maintenance. Journal: Int. J. of Reliability and Safety Pages: 55-85 Issue: 1 Volume: 18 Year: 2024 Keywords: SHM; structural health monitoring; sensor; data analytics; machine learning; durability; safety; maintenance; reliability. File-URL: http://www.inderscience.com/link.php?id=139199 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:1:p:55-85 Template-Type: ReDIF-Article 1.0 Author-Name: Ibrahim Yusuf Author-X-Name-First: Ibrahim Author-X-Name-Last: Yusuf Author-Name: Abdullahi Sanusi Author-X-Name-First: Abdullahi Author-X-Name-Last: Sanusi Author-Name: Alhassan Ibrahim Author-X-Name-First: Alhassan Author-X-Name-Last: Ibrahim Title: Performance analysis of client-server distributed system using Gumbel-Hougaard family Copula Abstract: The current paper compares the performance of two distinct client-server distributed system architectures using the capabilities of the Gumbel-Hougaard Family Copula. Using the Gumbel-Hougaard Family Copula, this paper presents a comprehensive comparative analysis of the performance of two distinct client-server distributed system architectures. The first architecture consists of three identical clients, a load balancer and three identical servers, whereas the second employs a three-component warm standby system with imperfect switching. The failure and repair patterns in both systems are exponential. The analysis entails using supplementary variable technique and Laplace transforms to solve first-order differential equations derived from transition diagrams for each system. While failures are distributed exponentially, repair times are represented by the versatile Gumbel-Hougaard Family Copula and a general distribution. The study considers various parametric values to evaluate various reliability metrics such as system availability, system reliability, Mean Time To Failure (MTTF), MTTF sensitivity and cost function. The findings are presented in the form of tables and figures, which provide a clear visual representation of the obtained insights. Journal: Int. J. of Reliability and Safety Pages: 19-54 Issue: 1 Volume: 18 Year: 2024 Keywords: architecture; client-server; distributed system; Gumbel-Hougaard; performance; reliability. File-URL: http://www.inderscience.com/link.php?id=139200 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:1:p:19-54 Template-Type: ReDIF-Article 1.0 Author-Name: Asheesh Tiwari Author-X-Name-First: Asheesh Author-X-Name-Last: Tiwari Author-Name: Ashish Sharma Author-X-Name-First: Ashish Author-X-Name-Last: Sharma Title: Growth model for detection and removal of faults having different severity with single change point and imperfect debugging Abstract: Throughout the last decades, researchers have modelled a variety of software reliability growth models for estimating measures of reliability. In the present paper, we have classied faults into four divergent types as per their easiness and hardness in detection and removal. Also, variations in fault detection and correction rates can be because of the testing strategy, changing testing environment, motivation, proficiency and organisation of the debugging and testing teams, etc. In the present paper, a change point has been applied to four types of faults along with imperfect debugging during the correction of faults. This paper comprises two proposed software reliability growth models, which are compared on the basis of rate of detection as well as correction. All the model parameters are evaluated by the method of least squares. These models are assessed using various comparison measures like SSE, MSE, RMSE, Bias, variance and RMSPE. Journal: Int. J. of Reliability and Safety Pages: 86-101 Issue: 1 Volume: 18 Year: 2024 Keywords: software reliability; software reliability growth model; change point; fault detection process; non-homogeneous Poisson process; sum of squared error; mean squared error; root mean square error; root mean square prediction error. File-URL: http://www.inderscience.com/link.php?id=139202 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:1:p:86-101 Template-Type: ReDIF-Article 1.0 Author-Name: Junxi Bi Author-X-Name-First: Junxi Author-X-Name-Last: Bi Author-Name: Xinyu Ge Author-X-Name-First: Xinyu Author-X-Name-Last: Ge Author-Name: Zenglin Hu Author-X-Name-First: Zenglin Author-X-Name-Last: Hu Author-Name: Jinfeng Li Author-X-Name-First: Jinfeng Author-X-Name-Last: Li Author-Name: Shaonan Yang Author-X-Name-First: Shaonan Author-X-Name-Last: Yang Author-Name: Hongwei Gao Author-X-Name-First: Hongwei Author-X-Name-Last: Gao Author-Name: Min Wu Author-X-Name-First: Min Author-X-Name-Last: Wu Title: Research on crack propagation of aircraft engine blades based on multi-physics field coupling and modal frequencies Abstract: With the continuous development of the aviation industry, crack propagation in aircraft engine blades has become an undeniable factor affecting aviation safety. In this study, a method based on multi-physics coupling and modal frequencies is proposed to investigate the characteristics and mechanisms of crack propagation in aircraft engine blades. Firstly, a numerical model based on finite element analysis and the Extended Finite Element Method (XFEM) is established to describe the multi-physics response and crack propagation behaviour of engine blades. Secondly, the proposed numerical model and analysis methods are utilised to conduct in-depth research on the characteristics and mechanisms of crack propagation in aircraft engine blades. Furthermore, modal frequency analysis is introduced to analyse the dynamic response and crack propagation mechanisms of the blades under different modes. Finally, the main achievements and contributions of the study on crack propagation of aircraft engine blades based on multi-physics coupling and modal frequency analysis are summarised, and future research directions are discussed. Journal: Int. J. of Reliability and Safety Pages: 103-120 Issue: 2 Volume: 18 Year: 2024 Keywords: engine blades; fatigue crack; natural frequency; fluid-structure coupling. File-URL: http://www.inderscience.com/link.php?id=139212 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:2:p:103-120 Template-Type: ReDIF-Article 1.0 Author-Name: Shuyuan Gan Author-X-Name-First: Shuyuan Author-X-Name-Last: Gan Author-Name: Nooshin Yousefi Author-X-Name-First: Nooshin Author-X-Name-Last: Yousefi Author-Name: David W. Coit Author-X-Name-First: David W. Author-X-Name-Last: Coit Title: Condition-based maintenance plan for multi-state systems using reinforcement learning Abstract: In this paper, a dynamic condition-based maintenance model is presented for a degrading system using a reinforcement learning approach. The system utilises a critical machine with multiple production states, which are estimated and obtained by some measurable indicators. Within the framework of the suggested maintenance policy, both the production state and machine virtual age are considered during the decision-making process for maintenance actions. The system is inspected at periodic times, and at each inspection, an action is selected from those that are available regarding spare parts and maintenance. Replacement and different levels of imperfect repairs are both considered. Additionally, the ordering of spare parts is also involved. The problem is formulated by using a discrete time Markov decision process and solved by the <em>Q</em>-learning algorithm. Numerical examples are provided to illustrate the proposed method. Also, the results indicate that the proposed method is time-saving and more cost-efficient than traditional methods. Journal: Int. J. of Reliability and Safety Pages: 144-162 Issue: 2 Volume: 18 Year: 2024 Keywords: dynamic maintenance; Markov decision process; Q-learning; spare parts; virtual age. File-URL: http://www.inderscience.com/link.php?id=139213 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:2:p:144-162 Template-Type: ReDIF-Article 1.0 Author-Name: R. Chitra Author-X-Name-First: R. Author-X-Name-Last: Chitra Author-Name: A.M. Anusha Bamini Author-X-Name-First: A.M. Anusha Author-X-Name-Last: Bamini Author-Name: D. Brindha Author-X-Name-First: D. Author-X-Name-Last: Brindha Author-Name: T.M. Chenthil Jegan Author-X-Name-First: T.M. Chenthil Author-X-Name-Last: Jegan Author-Name: S. Stewart Kirubakaran Author-X-Name-First: S. Stewart Author-X-Name-Last: Kirubakaran Title: Railway track fault detection using optimised convolution neural network Abstract: Railway accidents are an under-scrutinised cause of death in India. Train accidents are caused by various consequences of collisions, derailments, signal errors and so on. Furthermore, when train derailments become disastrous, they can have tremendous repercussions. It is practically difficult to identify the cause of the derailment efficiently within a limited period. In recent years, we have been making progress in reducing derailments, but even if not deadly, identifying faulty tracks can waste a lot of time and money. And doing this error-free is a pressing matter, as tracks always experience wear and tear with more usage. Here is where neural networks can pitch in their solution. We can train a model to look at train tracks and identify any issues. This paper goes into the methodology of achieving this and optimising a neural network to predict problems in the track with the best possible accuracy that images can provide. The objective of this paper is to identify, develop and optimise neural networks to detect faulty tracks. In this work, a good Convolution Neural Network model is developed to identify the crack in the railway track. The developed model produced 95.54% accuracy in fault classification. Journal: Int. J. of Reliability and Safety Pages: 163-186 Issue: 2 Volume: 18 Year: 2024 Keywords: activation function; track; neural network; optimisation; VGG. File-URL: http://www.inderscience.com/link.php?id=139215 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:2:p:163-186 Template-Type: ReDIF-Article 1.0 Author-Name: Jing Wu Author-X-Name-First: Jing Author-X-Name-Last: Wu Author-Name: Cunhua Qian Author-X-Name-First: Cunhua Author-X-Name-Last: Qian Author-Name: Tadashi Dohi Author-X-Name-First: Tadashi Author-X-Name-Last: Dohi Author-Name: Hiroyuki Okamura Author-X-Name-First: Hiroyuki Author-X-Name-Last: Okamura Title: An NPV analysis of opportunity-based age replacement model Abstract: This paper generalises the existing opportunity-based age replacement policies for a one-unit system by introducing the Net Present Value (NPV) of the expected total costs, where two cases are considered. First, we reformulate two basic opportunity-based age replacement models with replacement first and last disciplines, in which the failure time and the arrival time of a replacement opportunity are statistically independent. Next, we perform the NPV analysis for the failure-correlated opportunity-based age replacement models with replacement first and last disciplines. Since the NPV approach is useful to estimate more accurate replacement costs over a long-time planning in an unstable economic environment, we obtain the expected total discounted costs over an infinite time horizon and derive the optimal preventive replacement policies by minimising them in both cases. Numerical examples with the Farlie-Gumbel-Morgenstern bivariate copula are presented to investigate the dependence of correlation between the lifetime and the opportunistic replacement time on the opportunity-based age replacement policies. Journal: Int. J. of Reliability and Safety Pages: 121-143 Issue: 2 Volume: 18 Year: 2024 Keywords: net present value; age replacement; opportunity; correlation; bivariate distribution; replacement first; replacement last. File-URL: http://www.inderscience.com/link.php?id=139216 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:2:p:121-143 Template-Type: ReDIF-Article 1.0 Author-Name: Mohammadhasan Hedayati Author-X-Name-First: Mohammadhasan Author-X-Name-Last: Hedayati Author-Name: Mohammad Taghitahooneh Author-X-Name-First: Mohammad Author-X-Name-Last: Taghitahooneh Author-Name: Aidin Shaghaghi Author-X-Name-First: Aidin Author-X-Name-Last: Shaghaghi Author-Name: Reza Dashti Author-X-Name-First: Reza Author-X-Name-Last: Dashti Title: Influence of investment on failure rate in power distribution systems based on the value of assets Abstract: One of the important tasks of electricity distribution companies is to provide reliable electricity to all subscribers under their coverage. They must have proper management of their financial resources and their distribution. This asset management, in addition to helping to adjust and grow the technical indicators of the system, which increases the efficiency of the network, adds to the reliability, resilience and fair distribution of outages in the area covered by the network. In this article, we will analyse the value of network assets according to the budgeting rate of repairs and development. Also, the potential failure rate, i.e., the reduction in the financial value of a network's assets during one year caused by the delay in funding, will be expressed. This analysis helps us to know the impact of budgeting on the value of network assets during the lifetime of the equipment and to obtain the necessary budget limits for the fair distribution of financial resources in developed countries and the fair distribution of blackouts in developing countries. Also, the new depreciation rate obtained helps the decision-makers in electricity distribution systems to have proper planning and new policies to achieve the organisation's goals and increase customer satisfaction. Journal: Int. J. of Reliability and Safety Pages: 209-230 Issue: 2 Volume: 18 Year: 2024 Keywords: asset management; power distribution systems; failure rate; budgeting rate. File-URL: http://www.inderscience.com/link.php?id=139218 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:2:p:209-230 Template-Type: ReDIF-Article 1.0 Author-Name: Nabil El Akchioui Author-X-Name-First: Nabil El Author-X-Name-Last: Akchioui Author-Name: Hamid El-Moumen Author-X-Name-First: Hamid Author-X-Name-Last: El-Moumen Title: Reliability analysis of discrete model by continuous model: fluidisation approaches Abstract: This article addresses challenges in the reliability analysis of complex systems using stochastic models. Discrete models like stochastic Petri nets face difficulties in obtaining steady state analytical expressions due to the complexity of dynamic systems. To overcome this, the paper introduces fluidisation, employing continuous Petri nets for predicting stochastic processes' asymptotic behaviour. However, disparities arise in the asymptotic average markings between stochastic and continuous Petri nets with identical structures. The paper proposes two methods to approximate the steady state of similar stochastic Petri nets using continuous Petri nets. The adaptive approach dynamically adjusts firing speeds over time, while the geometric method delineates regions for a partial homothetic approximation of the stochastic steady state. These contributions enhance reliability analysis in complex systems by reconciling discrepancies between stochastic and continuous modelling. Journal: Int. J. of Reliability and Safety Pages: 187-208 Issue: 2 Volume: 18 Year: 2024 Keywords: reliability analysis; Markov model; combinatorial state explosion; stochastic Petri nets; continuous Petri nets; fluidisation; geometric approach; adaptive approach. File-URL: http://www.inderscience.com/link.php?id=139222 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:2:p:187-208 Template-Type: ReDIF-Article 1.0 Author-Name: Wenzhe Lai Author-X-Name-First: Wenzhe Author-X-Name-Last: Lai Title: Human-caused accident evaluation of coal mine safety relying on ant colony clustering algorithm Abstract: Through the analysis of numerous case samples, it is easy to find that the numerous reasons for the frequent occurrence of coal mine accidents are the human factors, and human-caused accidents have become the main cause of coal mine safety. The causes of human-caused accidents are very complex as well as the characteristic mechanisms of accidents are difficult to extract and carry out accurate data measurement, so the traditional engineering safety measurement methods have great limitations. They cannot accurately evaluate the causes of human-caused accidents in coal mines in the problem of high-dimensional pattern recognition. Based on this, the main work of the study focused on selecting the algorithm with good performance of simulated evolution-ant colony clustering algorithm as the technical support for the evaluation work, combining with the current mine production practice, four categories of factors from individual worker factors, environmental factors, life event factors and biological rhythm factors were clustered and analysed, scientific classification patterns as well as mathematical models were established to quantitatively analyse. The analysis of human misbehaviour is analysed and predicted. A behaviour correction model is established based on the human causes derived from the analysis so as to achieve the effect of accident prevention. Journal: Int. J. of Reliability and Safety Pages: 397-418 Issue: 4 Volume: 18 Year: 2024 Keywords: ant colony clustering knowledge recognition algorithm; coal mine safety; human accidents; individual factors. File-URL: http://www.inderscience.com/link.php?id=142056 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:4:p:397-418 Template-Type: ReDIF-Article 1.0 Author-Name: Xiong Wei Author-X-Name-First: Xiong Author-X-Name-Last: Wei Author-Name: Teng Wang Author-X-Name-First: Teng Author-X-Name-Last: Wang Author-Name: Xu Wang Author-X-Name-First: Xu Author-X-Name-Last: Wang Author-Name: Jiajun Ma Author-X-Name-First: Jiajun Author-X-Name-Last: Ma Author-Name: Guangjie Li Author-X-Name-First: Guangjie Author-X-Name-Last: Li Author-Name: Qiang Zhan Author-X-Name-First: Qiang Author-X-Name-Last: Zhan Author-Name: Dandan Wu Author-X-Name-First: Dandan Author-X-Name-Last: Wu Author-Name: Jiancun Zuo Author-X-Name-First: Jiancun Author-X-Name-Last: Zuo Title: Fuzzy fault tree analysis method of denitration system in thermal power plants Abstract: Denitration System (DS) is an important part of the production of thermal power plants, and any failure that occurs during its operation will seriously affect the productivity and safety of thermal power plants. Therefore, this paper proposes a Fuzzy Fault Tree (FFT) analysis method for DS of thermal power plants. Firstly, the theory of FFT is described, then the process flow of DS is introduced, the main faults in the operation of the system are analysed and the FFT is established for the main faults. The ambiguity of the basic event probability is solved by fuzzy set theory and expert judgment. After qualitative and quantitative analysis, the weak parts of the system and the degree of importance of the basic events are evaluated, so that it's of great significance to formulate protective measures in advance for the weak links of the system. Journal: Int. J. of Reliability and Safety Pages: 381-396 Issue: 4 Volume: 18 Year: 2024 Keywords: fuzzy fault tree; denitration system of thermal power plant; fuzzy number; language variables; expert evaluation; industrial safety. File-URL: http://www.inderscience.com/link.php?id=142066 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijrsaf:v:18:y:2024:i:4:p:381-396