Comprehensive Maintenance Research Articles

Study on improvement of the generator end fixed structure and optimization of pretightening process

To address recurring issues identified during comprehensive maintenance of a specific generator model—particularly the loosening of ring lead fixing structures at the generator ends, along with the detachment of felt and insulation wear—a detailed investigation was conducted. This study focused on analyzing the root causes of these problems and developing targeted improvement strategies. Taking the ring lead fixing structure as the research object, the investigation explored enhancements to the fixing structure and optimization of the bolt pretightening process. By comparing the fixing structure of faulty units with that of fault-free units and considering practical field conditions, a solution involving an increased cleat wrapping angle was proposed. The effectiveness of this improved design was verified through testing. Furthermore, the interaction of adjacent bolts during the stretching of single-head bolt stretchers was investigated for the bolt pre-tightening process. In view of the bolt pretightening process, the study explored the interaction between adjacent bolts when utilizing single-head bolt tensioners was studied, and experiments using multi-head synchronous hydraulic tensioners were conducted to evaluate their pretightening performance. The results revealed the pretightening behavior of multi-head systems, demonstrating their superior efficiency compared to single-head methods. These findings provide a robust foundation for applying such systems in industrial settings. This study aims to resolve technical challenges related to the ring lead fixing structure and the bolt pretightening process, ultimately ensuring the safe and stable operation of the generator.

Qualitative evaluation and corrective planning for centrifugal pump maintenance at Soekarno-Hatta airport

This study focuses on enhancing the maintenance processes of centrifugal pumps at Soekarno-Hatta Airport’s Water Treatment Unit in Indonesia, crucial for meeting the clean water needs of the airport, which served around 19.8 million passengers in 2022. Using a qualitative methodology, the research involved focus group discussions with the unit’s operators, technicians, and engineers to pinpoint maintenance challenges and devise solutions. Key findings reveal issues such as insufficient routine maintenance, unplanned repairs, and inadequate staffing, leading to operational disruptions and pump failures. The study highlights the role of Total Productive Maintenance (TPM) in reducing machine breakdowns and improving efficiency. It emphasizes the critical role of centrifugal pumps in the airport’s water supply system. The research proposes several corrective measures, adhering to the 5W + 1H framework, including regular lubrication, bearing replacements, hiring more staff, and advanced training on PLC systems. These actions aim to rectify immediate maintenance problems and establish a foundation for the long-term effectiveness of the pump systems. Conclusively, the study underscores the need for a comprehensive maintenance strategy that aligns with standard operating procedures and preventive maintenance. This approach is essential for boosting the operational performance and reliability of the Water Treatment Unit. It has broader implications for similar infrastructure facilities, underscoring the importance of efficient maintenance management.

Implementation of a Comprehensive Endovascular Aortic Programme and Maintenance of Clinical Excellence During Fenestrated Branched Endovascular Aortic Repair in Two Centres

Comprehensive endovascular aortic programmes need optimal infrastructure and multidisciplinary teams to manage complex aortic aneurysms. This study assessed the implementation of such a programme in two centres and its impact on fenestrated branched endovascular aortic repair (FB-EVAR) outcomes. A retrospective review of patients treated for complex abdominal and thoracoabdominal aortic aneurysms (TAAAs) by FB-EVAR between 2013 and 2023 was undertaken. All FB-EVAR patients were analysed, including investigational trials and high risk patients with physician modified endografts. Centre 1 (2013 - 2020) and Centre 2 (2020 - 2023) were compared. Primary endpoints were 30 day/in hospital mortality rate and major adverse events (MAEs). Secondary endpoints were procedural metrics, spinal cord injuries, freedom from all cause mortality, failure to rescue, and one year mortality rate and re-interventions. A total of 629 patients were included (475, 75.5% at Centre 1 and 154, 24.5% at Centre 2). Median age was 74 years (interquartile range 68, 79) and 441 (70%) were male. Centre 2 had a higher proportion of American Society of Anesthesiology class ≥ 3, genetically triggered aortic diseases (p = .002), chronic post-dissection aneurysms, prior aortic repairs, TAAAs (each p < .001), and symptomatic, larger aneurysms (p < .021). Technical success rates were similar between centres (98% vs. 98%; p = .91). Early mortality was 1.1% (7/629) with no statistically significant difference. No statistically significant differences (p > .050) in new onset permanent dialysis (0.6% vs. 2.0%), major stroke (0.6% vs. 0.6%), and permanent paraplegia (0.8% vs. 2.0%) were observed. Failure to rescue rates were 5% in Centre 2 and 3.5% in Centre 1 (p = .74). The one year mortality rate (91% vs. 89%; p = .71) and re-intervention rate (SHR 1.30; p = .21) were similar between centres. Fenestrated branched endovascular aortic repair was performed with a low mortality rate and risk of disabling complications. No differences in mortality rate and MAEs were observed after establishing a comprehensive endovascular programme, despite higher risk and more extensive cases at the new institution.

3D GPR Detection and Case Analysis of Collapse Hazards for an International Airport Runway

Abstract The safety of airport runways is crucial for ensuring the operation of airports and the safety of aircraft flights during taking off and landing. All current methods for assessing airport runways primarily focus on surface routine inspections or surveys, lacking both the capability and available technologies for comprehensive detection of runway and its underground conditions. In this paper, considering a specific airport runway in China that experienced collapse hazards due to cavities, three-dimensional ground-penetrating radar (3D GPR) is explored for detecting potential hazards on the runway and its surroundings. By analyzing the detection data, the formation and distribution of collapses were examined clearly based on B-scan and C-Scan, and then assessed obviously the safety conditions of the airport runway. The research work and its findings provide a new valuable insight of NDT method for guiding comprehensive inspections and maintenance of large airport runways.

Holistic opportunistic maintenance scheduling and routing for offshore wind farms

Despite the high growth of the offshore wind market, the economic benefits of wind energy sources are still being undermined by its high operation and maintenance expenses. On the one hand, high maintenance expenses are a direct result of offshore-specific challenges such as complex ocean meteorology, varying vessel accessibility, and shifting transportation requirements. Besides, component degradation and weather conditions largely limit the ability of turbine operators to estimate a workable maintenance time window. This study aims to develop a holistic opportunistic maintenance strategy to address the practical challenges of offshore wind farms. The proposed strategy starts by deriving the preventive maintenance interval of each turbine component based on its degradation trend and predictable cost rates. Then, each turbine is maintained in groups based on the maintenance opportunities arising from preventive maintenance, unexpected failures, and cable damage. Following that, given weather condition forecasts of key parameters (wind speed and wave height), the proposed strategy optimizes the daily allocations and vessel routes to maintain turbines in a timely and cost-effective manner. Finally, experimental results based on real-world data from an actual offshore wind farm demonstrate that the proposed strategy outperforms several universal maintenance strategies in key metrics. Compared to the simple, widely employed, and easy-to-implement strategies, it can help reduce the total cost by 85.9 %, 65.9 %, and 41.6 %, respectively. This work helps turbine operators implement comprehensive and cost-effective maintenance schemes, which can lead to tariff duction and wind farm promotion benefits in the long term.

Методичні підходи до визначення вартості послуг з утримання пунктів пропуску через державний кордон для автомобільного сполучення

Introduction. The article examines the methodology for determining the cost of services for maintaining border crossing points for road transport. The research highlights the importance of establishing effective resource needs to ensure the uninterrupted operation of these points, which is critical for national security and Ukraine’s economic development. Problem Statement. Given the current development of the infrastructure sector, determining the cost of comprehensive maintenance and technical servicing of buildings, structures, and adjacent areas within a road border crossing point is of particular importance. Ensuring the smooth and efficient operation of these points requires a systematic approach to evaluating provided services and developing a methodology that takes into account various aspects of maintaining and servicing infrastructure objects. Analyzing the cost of such services becomes a crucial stage in planning and effective resource management, as it affects service quality, availability, and competitiveness. Therefore, there is an urgent need to develop a scientifically sound methodology for determining service costs, considering the specificities of these facilities' operation.

Методичні підходи до визначення вартості послуг з утримання пунктів пропуску через державний кордон для автомобільного сполучення

Introduction. The article examines the methodology for determining the cost of services for maintaining border crossing points for road transport. The research highlights the importance of establishing effective resource needs to ensure the uninterrupted operation of these points, which is critical for national security and Ukraine’s economic development. Problem Statement. Given the current development of the infrastructure sector, determining the cost of comprehensive maintenance and technical servicing of buildings, structures, and adjacent areas within a road border crossing point is of particular importance. Ensuring the smooth and efficient operation of these points requires a systematic approach to evaluating provided services and developing a methodology that takes into account various aspects of maintaining and servicing infrastructure objects. Analyzing the cost of such services becomes a crucial stage in planning and effective resource management, as it affects service quality, availability, and competitiveness. Therefore, there is an urgent need to develop a scientifically sound methodology for determining service costs, considering the specificities of these facilities' operation.

Characterizing Unique Clinical and Virological Profiles in Concurrent Chronic Hepatitis B and Metabolic Dysfunction-Associated Liver Disease: Insights from a Population-Based Cohort Study.

Background: The concurrent presence of chronic hepatitis B virus (CHB) infection and metabolic dysfunction-associated steatotic liver disease (MASLD) presents a unique clinical scenario with implications that are not yet fully understood. This study aims to characterize the distinct clinical and virological features of CHB in the context of MASLD and evaluate its impact on disease progression and outcomes. Methods: Utilizing a comprehensive health maintenance organization database, this study included 1186 patients with CHB from 2000-2020. Patients were categorized into two groups: CHB-MASLD (n = 188) and CHB alone (n = 998). CHB diagnosis was confirmed by serological markers, while MASLD was diagnosed based on imaging and cardiometabolic risk factors. Comparative analysis and multiple regression models were applied to assess variables related to viral parameters and clinical outcomes. Results: The CHB-MASLD group was older (mean age of 45.2 vs. 39.1, p < 0.001) with higher rates of obesity (46.8% vs. 23.8%, p < 0.001), diabetes (36.2% vs. 17.3%, p < 0.001), and dyslipidemia. Distinct viral profiles included higher HBeAg negativity (96.2%), a higher rate of HBeAg-negative infection (70.4% vs. 63.8%; p < 0.001), and increased HBeAg seroconversion under treatment. Cirrhosis was more prevalent in the CHB-MASLD group (9.6% vs. 4.4%, p = 0.007), while HCC rates were comparable. Multivariate analysis identified age, male gender, chronic active hepatitis, and diabetes as predictors of cirrhosis. Conclusions: CHB-MASLD patients were distinguished by a higher prevalence of metabolic features, along with a distinct viral profile marked by increased chronic HBeAg infection, higher rates of HBeAg seroconversion, and a potential association with worse disease outcomes.

The Modeling and Optimization of a Multi-dam System

In this paper, we present a maintenance plan for the Kariba Dam in Africa. The Kariba Dam, a double curvature concrete arch dam in Zambia&amp;apos;s capital, is crucial for regional energy and water management. Ensuring its safety and functionality is essential. This study provides a comprehensive analysis and maintenance plan to safeguard the dam&amp;apos;s long-term viability. Our mathematical analysis begins with a threshold evaluation of three proposed options, considering costs such as relocation, dam removal, construction of new dams, repairs, and ecological damage, as well as benefits like energy generation, flood prevention, employment, tourism, and ecological protection. The data-driven analysis indicates that our option is the most economically viable. We assess water management capabilities, using them as a safety coefficient for the dams. We selected 30 seed points along the riverbank to establish dams. Our recommendation is to increase the number of dams and ensure their strategic distribution. An assessment model based on the analytic hierarchy process was then developed, focusing on three factors: safety, economy, and population. We determined the weights of each factor. The optimal scheme was identified through this model, and the sensitivity of the results was also evaluated. The greatest impact under extreme conditions was found. This paper provides the details of the theoretical analysis and the numerical experiments, which include the use of modeling, optimization, mathematical programming, and so on.

Assessing PV inverter efficiency degradation under semi-arid conditions: A case study in Morocco

The worldwide shift towards renewable energy sources, including solar and wind, is progressing rapidly. This change is driven by decreasing prices and technical advancements that are becoming more centralized. The objective is to develop a cutting-edge approach and technology that seamlessly incorporates photovoltaic (PV) energy sources into a power network while ensuring grid stability. This research evaluates the lifetime and degradation of PV inverters under real operating conditions, focusing on semi-arid climate scenarios. Current papers demonstrate a yearly failure rate of 1–15% for PV inverters, highlighting the need for a thorough reliability evaluation. This investigation research applied a unique technique that included continuous monitoring of PV inverter performance parameters by comparing the measured with the predicted normal operating output. The results show that Sandia's inverter performance model is highly suitable for accurately modeling normal PV inverter behavior. Furthermore, weighted efficiency dropped by 3.96%, 0.63% and 1.29% respectively for 7kW, 15kW and 20kW photovoltaic systems over the five years. These findings have implications for comprehensive maintenance strategies, including regular inspections, safety protocols, and remote monitoring solutions. Ultimately, this research paper sheds light on the causes of declining solar inverter performance and provides suggestions for enhancing PV plant maintenance and reliability. It also represents an outstanding reference given the literature shortage.

Research on Digital Greening Management of Smart Gardens in Chenggong District, Kunming City

With the rapid urbanization in China, city scales have expanded, bringing numerous management challenges. The continuous expansion of urban green spaces highlights the difficulty of adapting traditional urban garden management to complex conditions. The solution lies in using AI and big data for smart city management, specifically termed 'Smart Gardens'. This system integrates modern information technology into daily urban garden management. Through platform management systems, it enables comprehensive planning, construction, maintenance, supervision, and service of urban green spaces. This ensures real-time data updates, visualized management, and dynamic services. This digital transformation is essential. This paper analyzes the current issues and future development strategies of digitalized garden management in Chenggong District, Kunming. Through literature review, field research, and data collection, it aims to enhance the green space management in Chenggong District and other regions.

Research on the Talent Training Mode of High Speed Rail Comprehensive Maintenance Technology Professional Group under the Background of "Double High"

The purpose of this paper is to explore the talent cultivation mode of high-speed rail comprehensive maintenance technology professional group under the background of "dual high". Firstly, the value logic of vocational colleges under the background of "dual high" was analyzed, and the construction background of the comprehensive maintenance technology professional group for high-speed rail was analyzed. Next, the difficulties faced by the reform of talent cultivation mode under the background of "dual high" were discussed. Finally, a construction strategy for a high-level comprehensive maintenance technology professional group for high-speed rail was proposed, aiming to provide valuable ideas and suggestions for promoting the development of the high-speed rail industry.

Mileage-Aware for Vehicle Maintenance Demand Prediction

It is of paramount importance to accurately predict the maintenance demands of vehicles in order to guarantee their sustainable use. Nevertheless, the current methodologies merely predict a partial aspect of a vehicle’s maintenance demands, rather than the comprehensive maintenance demands. Moreover, the process of predicting vehicle maintenance demands must give due consideration to the influence of mileage on such demands. In light of the aforementioned considerations, we put forth a vehicle overall maintenance demand prediction method that incorporates vehicle mileage awareness. In order to address the discrepancy between the vector space of mileage and that of the project, we put forth a mileage representation method for the maintenance demand prediction task. To capture the significant impact of key mileage and projects on future demand, we propose a learning module for key temporal information using a fusion of Long Short-Term Memory (LSTM) networks and attention mechanism. Moreover, to integrate maintenance mileage and projects, we propose a fusion method based on a gated unit. The experimental results obtained from real datasets demonstrate that the proposed model exhibits a superior performance compared to existing methods.

Strategizing Effective Maintenance Strategies for Air Conditioning Systems in Commercial Buildings in Malaysia: A Systematic Literature Review

The use of air conditioning systems is prevalent in many locations in Malaysia due to the elevated temperatures seen in the region. The importance of air conditioning system maintenance has not been accorded due attention. Taking this issue into consideration, this study aims to enhance the maintenance of air conditioning systems by understanding their importance, identifying maintenance issues and proposing solutions to enhance system maintenance, with a specific focus on commercial buildings in Malaysia. The data used in the study was gathered from case studies, images, newspapers, journals and previous theses. This study used fully qualitative methods to obtain data and was acquired through a systematic literature review (SLR) and open-ended interview questionnaire with experts. From the findings, it was found that there were three main strategies, which are preventive maintenance, corrective maintenance and predictive maintenance that are mostly applied for the maintenance of the air conditioning system at the commercial building in Malaysia. The overall findings from the interview with experts highlighted that technical expertise, specialized tools and comprehensive maintenance strategies were important elements to be employed by HVAC technicians and facility managers in Malaysia when managing the HVAC, especially the air conditioning system. This research expands knowledge by investigating air conditioning system maintenance. Furthermore, the findings of this study are useful to the maintenance team and users since they provide the best strategies for the maintenance of the air conditioning systems of commercial buildings in Malaysia.

A Bayesian framework for in-flight calibration and discrepancy reduction of spacecraft operational simulation models

Modeling and Simulation (M&S) tools have become indispensable for the comprehensive design, operations, and maintenance of products in the space industry. An example is the European Space Agency (ESA), which relies heavily on M&S throughout the entire lifecycle of a spacecraft. However, their use in operational settings poses significant challenges, mainly attributable to (i) the harsh, uncontrollable, and often unforeseen environmental conditions; (ii) the dramatic changes in operating conditions throughout a spacecraft’s lifespan, often beyond the intended designed-for lifetime; and (iii) the presence of epistemic and aleatoric uncertainty. This results in unavoidable discrepancies between the numerical simulations and real measurements, limiting their use for delicate operational tasks. To address those challenges, we present a Bayesian framework for simultaneous calibration of M&S tools, reduction of the model discrepancy, and quantification of the process and model uncertainties. The approach leverages the Kennedy and O’Hagan (KOH) calibration, tailored for a multi-objective problem. Its effectiveness is shown by its application to flying Earth observation spacecraft data and the operational simulation models.

Application of CNN for multiple phase corrosion identification and region detection

Corrosion is a significant issue that contributes negatively to the degradation of materials most especially metals. To ensure proper maintenance, enhance reliability and prevent breakdown, it is very essential to not only effectively detect corrosion but to also understand its locations and distributions on the materials. A Multiple phase Convolutional Neural Network (CNN) model is created for this purpose. The Multiple phase CNN model consists of custom designed deep learning algorithms at various stages. This created the opportunity to make use of binary classification, multi-label classification and patch distribution algorithm to detect and identify corrosion regions on metallic materials. Six (6) different labels of corrosion were modelled to represent different levels of degradation using 600 anonymized images. The images were used in the various stages of the framework for training the respective models. Results at the binary level shows 94.87 % of corrosion detection. The multiclass stage of the Multiple phase CNN records the highest accuracy of 92.1 %. The patch distribution stage recorded a highest accuracy of 96.5 % and 94.6 % for the Average Image and Average Pixel ROCAUC (Region of Concentration Area Under Cover). It also shows a region segment average accuracy detection of 91.5 % (image level) and 89.2 %(pixel level) for 9 distinct regions. The research provides a comprehensive and detailed reliability and maintenance information for Aerospace, Transport and Manufacturing Materials experts and non-experts. The framework shows a robust approach to detecting corrosion which is essential for critical and safety applications as well as preventing economic loss due to corrosion. This can also be extended to other domains beyond the corrosion case study.

Penerapan Strategic Approach Pada Kegiatan Company Visit PT. Garuda Maintenance Facility Aero Asia Tbk

PT Garuda Maintenance Facility Aero Asia Tbk (GMF) is a company engaged in aircraft maintenance, repair and overhaul (MRO). GMF has a business unit consisting of comprehensive aircraft maintenance, such as commercial aircraft maintenance, military aircraft maintenance and industrial services. At this company, the author took part in practical work activities in the Corporate Communications &amp; CSR unit which is under the auspices of the Corporate Secretary &amp; Legal service which carries out the public relations function at GMF. In this report, the author will explain the application of 4 strategic approaches to company visits held for GMF stakeholders using interview, observation and literature study methods. The stakeholder aspects that will be explained from the perspective of Grunig's 4 Linkage Model are functional linkage, enabling linkage, normative linkage, and diffused linkage. PT GMF approaches stakeholders using 4 strategic approaches, namely assertive, defensive, collaborative and responsive.

Practical use of Agriculture 4.0 digital technologies to meet the EU's strategic goals in Czech agriculture

The implementation of precision technology procedures is declared in EU documents, including the implementation of these technologies in all areas of production, production, trade, including all areas of everyday life of the population. The article deals with the use of IT technologies in activities dealing with land management: i.e. crop production including landscape maintenance. In this context, precision technologies are used in agriculture, crop and livestock production, horticulture, forestry and comprehensive maintenance of the agricultural landscape. With remote sensing, all land areas are monitored, data is stored, and the whole process takes place continuously. The data is displayed in information maps that perfectly map the properties of the monitored area. Today, the development of the information society and specialized internet services of the state administration would not be possible without precise technologies and information portals. These are portals for the public needs of citizens or a specific professional community, and these must be user-friendly, clear, intuitive, visually interesting, trustworthy and complete in content. The article deals with a detailed analysis of the Czech Farmer's Portal from multiple angles, including state-of-the-art tools such as the AMS system (AMS, 2023). This is a new way of monitoring agricultural areas using a satellite system. On the basis of the analysed services, deficiencies are identified and suggestions for improvement are presented.

Balancing the maintenance strategies to making decisions using Monte Carlo method

This study aims to develop comprehensive maintenance strategies tailored to enhance the dependability, performance, and lifespan of critical assets within industrial and organizational settings. By integrating proactive, preventive, predictive, and corrective maintenance tactics, our strategy seeks to minimize downtime, reduce costs, and optimize asset performance. Drawing from extensive case studies across various industrial sectors, our research utilizes robust data analysis to inform strategy development.We employ mathematical cost models and simulations using the Monte Carlo Method in MATLAB to evaluate the performance and robustness of different maintenance strategies, including time-based and condition-based approaches. Our findings demonstrate that a holistic maintenance approach significantly improves operational efficiency and asset longevity. Specifically, our analysis reveals that integrated maintenance strategies lead to reduced downtime, lower maintenance costs, and enhanced asset reliability.Policy implications of our research suggest that organizations should adopt integrated maintenance strategies to enhance asset reliability and performance, ultimately achieving sustained operational excellence. By emphasizing the importance of proactive maintenance measures alongside traditional reactive approaches, organizations can effectively manage their critical assets, leading to improved operational outcomes and long-term success.–Integration of proactive, preventive, predictive, and corrective maintenance tactics–Evaluation of performance and robustness through mathematical cost models–Application of the Monte Carlo Method in MATLAB for comparative analysis

The Impact of Lean Manufacturing Practices in Enhancing Sustainable Performance through Lean Culture: Field Study at the General Company for Food Products – Baghdad

The study aimed to determine the effect of lean manufacturing practices in enhancing sustainable performance by mediating the lean culture in the General Company for Food Products in Baghdad, the field of study represented by the factories (Al-Maamoun, Al-Rasheed, and Al-Amin), where the study included the independent variable of lean manufacturing practices in their dimensions (comprehensive productive maintenance, map). Value flow, production on time, speed of preparation and preparation) in achieving sustainable performance in its dimensions (economic performance, social performance, environmental performance) by mediating the lean culture in its dimensions (continuous improvement, organizing the work site, reducing waste, and lean thinking). The study attempted to answer the questions that express the problem of the study, including: Is there an effect of lean manufacturing practices and the lean culture in achieving sustainable performance? The questionnaire was distributed to a sample of technicians in the company’s factories in the field of study. The study relied on the questionnaire as the main tool for collecting data through a random sample that included (218) technicians working in the factories under study. Some statistical methods were used for the two ready-made programs (SPSS, v.28, AOMS, V.26(. The study results that the primacy of the variables based on their relative importance, as they were respectively (lean culture, lean manufacturing, and sustainable performance). The results of the study showed that there is an effect of lean manufacturing practices in sustainable performance through the lean culture, The Food Industries Company was able to reduce unnecessary activities by using a lean culture to reduce waste, and this led to improving and sustaining performance in the company’s field of study.