Reliability-centered Maintenance Strategy Research Articles

Optimal reliability-centered maintenance strategy based on the failure modes and effect analysis in power distribution systems

Owing to the impressive development in the electricity distribution network, the managers of the system should be able to handle the costs of the network effectively. The practical implementation of the reliability-centered maintenance is one of the ways to address this concern. In this paper, we initially use the multi-criteria decision-making method of gray relative analysis to prioritize failure modes and obtain their risk factor in the network. Various failure modes in network equipment such as insulators, jumpers, cutout fuses, switches, transformers, and the cables are considered. Then, to select optimal strategies for each failure mode, we present an optimization based on the energy not supplied of electrical distribution feeder, the maintenance cost, the outage cost, the safety cost and the risk factor of failure modes. Hotline, coldline, and neutral are among the strategies to be implemented in the current research. To show the effectiveness of the proposed method, we utilize various scenarios to investigate the impacts of maintenance duration, hotline safety costs and practical restrictions on the results. Findings indicate that total maintenance costs, compared to those of the business as the usual strategy, can be reduced by at least 7% when the propose method is applied.

Appropriate strategy selection for reliability-centered maintenance of one-shot systems using fuzzy model

PurposeThis paper addresses special reliability-centered maintenance (RCM) strategies for one-shot devices by providing fuzzy inferences system with the assumption that, to data, there is no data available on their maintenance. As far as one-shot devices are concerned, the relevant data is inadequate.Design/methodology/approachIn this paper, a fuzzy expert system is proposed to effectively select RCM strategies for one-shot devices. In this research: (1) a human expert team is provided, (2) spatial RCM strategies for one-shot devices and parameters bearing upon those strategies are determined, (3) the verbal variables of the expert team are transformed into fuzzy sets, (4) the relationship between parameters and strategies are designed whereupon a model is developed by MATLAB software, (5) Finally, the model is applied to a real-life one-shot system.FindingsThe finding of this study indicates that the proposed fuzzy expert system can determine the parameters affecting the choice of the appropriate one-shot RCM strategies, and a fuzzy inference system can help for effective decision making.Originality/valueThe developed model can be used as a fast and reliable method for determining an appropriate one-shot RCM strategy, whose results can be relied upon with a suitable approximation in respect of the behavior test. To the best authors’ knowledge, this problem is not addressed yet.

Productivity Improvement of Transmission Electron Microscopes - A Case Study

This paper aims to improve the performance of Transmission Electron Microscopes (TEM) used in asbestos detection processes in a business context. Failure Modes and Effects Analysis (FMEA) were studied, identifying the critical failure modes, proposing risk reduction measures and changing maintenance practices based on the Reliability Centered Maintenance strategy. In the elaboration of the FMEA it was evident the lack of data and poor information quality regarding the reliability and maintenance of TEM. These circumstances led to the implementation of training projects to standardize operations and to the development of a software application for data collection and reports generation with relevant performance indicators (Costs, Mean Down Time, Overall Equipment Effectiveness, …) to support operators tasks and decision-making. The approach followed and the tools developed allowed monitoring TEM productivity and maintenance performance. As a result, more informed decisions can be made that will lead to improved performance of TEM.

Application of Reliability-Centered Maintenance in Metro Door System

Metro door system (MDS) is one of the most important and fault-prone parts of metro train. Reliability-centered maintenance (RCM) is a systematic engineering process for determining the preventive maintenance requirements of equipment and optimizing the maintenance system. This paper is motivated to apply RCM to the maintenance of metro door system. Firstly, the subsystems and components of MDS are introduced. Then a fuzzy FMECA method is proposed to define the hazard degree of 10 failure modes from 5 components with high failure rate to conduct reliability analysis. Finally, reliability-centered maintenance strategy is made after maintenance mode decision and calculation of maintenance interval cycle, which provides theoretical basis to the maintenance of the metro train.

Mission Reliability-Oriented Selective Maintenance Optimization for Intelligent Multistate Manufacturing Systems With Uncertain Maintenance Quality

Selective maintenance is widely used as a reliability-centered maintenance strategy due to the limited maintenance resources. However, existing selective maintenance studies only consider basic reliability, which cannot systematically describe the operating mechanism of a multistate system, thereby resulting in the inability to obtain an optimal maintenance strategy. Moreover, intelligent manufacturing systems are highly representative of typical multistate industrial systems. In this study, a mission reliability-oriented selective maintenance optimization model for intelligent manufacturing systems that considers the uncertain maintenance effect was proposed. First, a new connotation and modeling method for mission reliability based on multistate system theory was presented to comprehensively characterize the operating mechanism of intelligent manufacturing systems. Second, a quantitative model between maintenance resources and quality based on real-time data was established to reflect the uncertain characteristics caused by repairmen and tools. Third, a selective maintenance decision model of a multistate manufacturing system was developed under the constraints of maintenance cost and time. This constraint combination optimization problem was solved using the particle swarm optimization algorithm. Finally, a case study of selective maintenance optimization for a cylinder head manufacturing system was presented to verify the proposed method.

Development of the algorithm of reliability­centered maintenance of phased array antennas

The strategy and algorithm of reliability-centered maintenance of active phased array antennas are developed. The use of this strategy and algorithm makes it possible to determine the time and volumes of corrective replacements of the antenna subarray modules based on the results of predicting the reliability indexes of the array antenna as a whole. This procedure is performed as a result of consistent refinement of statistical estimates of reliability indexes of the modules during the normal operation of the phased array antenna. For processing statistical information on the failures of the array antenna modules and determining the estimates of the sample mean, upper and lower confidence limits, the method of quantiles is used. As the law of distribution of the operating time of the array antenna modules, the combination of exponential and diffusion nonmonotonic distributions is used. The example of implementation of the reliability-centered maintenance strategy and algorithm for the receive phased array antenna including 100 antenna subarrays is presented. The results of the research can allow organizing the APAR condition-based maintenance and minimizing the operating costs. Implementation of the obtained results can ensure failure-free operation of active phased array radars during operation with the timely provision of antenna subarrays with spare modules.

Application of Reliability Centered Maintenance Strategy to Safety Injection System for APR1400

Application of Reliability Centered Maintenance Strategy to Safety Injection System for APR1400

Implementing a Strategy of Reliability Centered Maintenance (RCM) in the Libyan Cement Industry

The substantial development of the construction industry has forced the cement industry, its major support, to focus on achieving maximum productivity to meet the growing demand for this material. This means that the reliability of a cement production system needs to be at the highest level that can be achieved by good maintenance. This paper studies the extent to which the implementation of RCM is needed as a strategy for increasing the reliability of the production systems component can be increased, thus ensuring continuous productivity. In a case study of four Libyan cement factories, 80 employees were surveyed and 12 top and middle managers interviewed. It is evident that these factories usually breakdown more often than once per month which has led to a decline in productivity. In many times they cannot achieve the minimum level of production amount. This has resulted from the poor reliability of their production systems as a result of poor or insufficient maintenance. It has been found that most of the factories' employees misunderstand maintenance and its importance. The main cause of this problem is the lack of qualified and trained staff, but in addition it has been found that most employees are not found to be motivated as a result of a lack of management support and interest. In response to these findings, it has been suggested that the RCM strategy should be implemented in the four factories. The results show the importance of the development of maintenance strategies through the implementation of RCM in these factories. The purpose of it would be to overcome the problems that could secure the reliability of the production systems. This study could be a useful source of information for academic researchers and the industrial organizations which are still experiencing problems in maintenance practices.

English

Among different maintenance strategies that exist for power distribution systems, the Reliability-Centered Maintenance (RCM) strategy attempts to introduce a structured framework for planning maintenance programs by relying on network reliability studies and cost/benefit considerations. For the implementation of the RCM strategy, the electricity distribution companies try to optimally utilize the existing financial resources in order to reduce the maintenance costs and improve the reliability of the network. The aim of this paper is to present a practical method for devising an appropriate maintenance strategy for network elements and for preventive maintenance budget planning, with the goal of improving the system reliability and reducing the maintenance costs. In the proposed method, the critical outage causes of the distribution system are determined on the basis of cost and reliability criteria, by the Technique for order preference by similarity to ideal solution (TOPSIS) method. Then, the optimum preventive maintenance budget is calculated by obtaining the cost functions of the critical elements and optimizing the overall cost function. In this investigation, the medium voltage distribution network of the “Haft Tir” district in Tehran has been chosen for the implementation of the proposed RCM strategy. Key words: Reliability-centered maintenance (RCM), preventive maintenance (PM), technique for order preference by similarity to ideal solution (TOPSIS), power distribution system.

Reliability‐centred maintenance for circuit breakers in transmission networks

Reliability of power system can be influenced by the maintenance strategy adopted for the system's equipments. This study focuses on power circuit breakers maintenance planning based on the concept of reliability-centered maintenance (RCM) and applies the proposed approach on the 400 kV transmission network in Khorasan province in Iran. The RCM strategy takes into account the technical condition and importance of each circuit breaker from the network's perspective. The technical condition index of a specific circuit breaker is a numerical representation of the physical health of the breaker and can be evaluated by some criteria. To determine this index, the performance of the circuit breakers during interval 2007–2012 is considered. The importance of each circuit breaker is related to the consequence of its failure on the network. As the main drawback of the available researches in this area is the lack of a generic tool to determine the importance of the circuit breakers, this study proposes a three-stage procedure to accurately evaluate the importance of the circuit breakers. The main idea in the proposed approach is to analyse all failure modes of the circuit breakers and simulate the effect of each failure mode on the overall expected energy not served. The obtained results show the efficiency of the proposed approach.

Developing RCM strategy for wind turbines utilizing e-condition monitoring

The number of offshore wind turbines installed in the seas around Britain’s coasts is likely to increase from just fewer than 150 to 7,500 over the next 10 years with the potential cost of £10 billion. Operation and Maintenance activities are estimated to comprise 35 % of the cost of electricity. However, the development of appropriate and efficient maintenance strategies is currently lacking in the wind industry. The current reliability and failure modes of offshore wind turbines are known and have been used to develop preventive and corrective maintenance strategies which have done little to improve reliability. Unplanned maintenance levels can be reduced by increasing the reliability of the gearbox and individual gears through the analysis of lubricants. In addition, the failure of one minor component can cause escalated damage to a major component, which can increase repair and or replacement costs. A Reliability Centered Maintenance (RCM) approach offers considerable benefit to the management of wind turbine operations, since it includes an appreciation of the impact of faults on operations. Due to the high costs involved in performing maintenance and the even higher costs associated with failures and subsequent downtime and repair, it is critical that the impacts are considered when maintenance is planned. The paper will provide an overview of the application of RCM and on line e-condition monitoring to wind turbine maintenance management. Finally, the paper will discuss the development of a complete sensor-based processing unit that can continuously monitor the wind turbine’s lubricated systems and provide, via wireless technology, real-time data enabling onshore staff the ability to predict degradation, anticipate problems, and take remedial action before damage and failure occurs.

Implementation of Reliability-Centered Maintenance for transmission components using Particle Swarm Optimization

In a deregulated power industry, a maintenance strategy is of critical importance for transmission systems composed of aging components. Such a strategy can provide significant cost savings by optimizing maintenance decisions for power system operation. This paper presents a Reliability-Centered Maintenance (RCM) model for developing a maintenance strategy in a transmission system. This model is applicable to transmission components whose degradation can be classified according to the severity of the aging. Particle Swarm Optimization (PSO) is used to extract the optimal RCM strategy from a large class of possible maintenance scenarios. A numerical example shows that a maintenance strategy based on the proposed RCM model is more cost-efficient than traditional maintenance strategies.

Research on Maintenance Strategy of Large-Scale Grab Ship Unloader Based on Reliability

t is hard to acquire the failure data of ship unloader and the mean time to failure is not independent identically distributed, and there are many defects existed in the maintenance method such as high cost and bad effect. In this work, we propose a method based on Weibull Distribution model to deal with the failure data of a large-scale grab ship unloader, build up the model of MTBF (Mean Time Between Failure) and preventive maintenance time, and show the example with failure data, which provides references to maintenance of the ship unloader. Finally, we present the decision process of the reliability-centered maintenance strategy, maintenance type of the grab ship unloader and the maintenance of the key parts, which provides scientific decision support for the maintenance of the ship unloader equipments.

Developing RCM Strategy for Hydrogen Fuel Cells Utilizing On Line E-Condition Monitoring

Fuel cell vehicles are considered to be a viable solution to problems such as carbon emissions and fuel shortages for road transport. Proton Exchange Membrane (PEM) Fuel Cells are mainly used in this purpose because they can run at low temperatures and have a simple structure. Yet high maintenance costs and the inherent dangers of maintaining equipment using hydrogen are two main issues which need to be addressed. The development of appropriate and efficient strategies is currently lacking with regard to fuel cell maintenance. A Reliability Centered Maintenance (RCM) approach offers considerable benefit to the management of fuel cell maintenance since it includes an identification and consideration of the impact of critical components. Technological developments in e-maintenance systems, radio-frequency identification (RFID) and personal digital assistants (PDAs) have proven to satisfy the increasing demand for improved reliability, efficiency and safety. RFID technology is used to store and remotely retrieve electronic maintenance data in order to provide instant access to up-to-date, accurate and detailed information. The aim is to support fuel cell maintenance decisions by developing and applying a blend of leading-edge communications and sensor technology including RFID. The purpose of this paper is to review and present the state of the art in fuel cell condition monitoring and maintenance utilizing RCM and RFID technologies. Using an RCM analysis critical components and fault modes are identified. RFID tags are used to store the critical information, possible faults and their cause and effect. The relationship between causes, faults, symptoms and long term implications of fault conditions are summarized. Finally conclusions are drawn regarding suggested maintenance strategies and the optimal structure for an integrated, cost effective condition monitoring and maintenance management system.

A reliability centered maintenance strategy for a discrete part manufacturing facility

A specialized maintenance decision support system based on Reliability Centered Maintenance (RCM) and the US dept. Of Defense's Failure Mode, Effect and Criticality Analysis (FMECA) has been developed. It was constructed using a modular approach which uniquely integrates the virtues of RCM and FMECA to perform the failure analysis function. A Logic Tree Analysis (LTA) module supports the decision process by performing Cost and Maintainability evaluation to promote the most appropriate maintenance tasks. The Maintenance Planning Module applies “Theory of Constraints” to fit tasks into the production schedule. Apart from a conventional focus on addressing operational failure modes, it takes environmental impact and human safety concerns into perspective in developing tasks directed at achieving higher levels of equipment availability and effectiveness. Ultimately, it contributes to higher quality product manufactured at a significantly lower overall cost. Initial field test results for Miami, Florida based manufacturing system are reviewed.