Models of Functional Checks of Plant with Hidden Function Failure

1IntroductionUsually,maintenancemodelsarebase(lontwok-mdsofslateoftheplallltfltorlnaland.failure(maintenance).Infact,thestateofplantchangeswiththeincreaseofusetimes.Itisnotaccuratetodividethestateofplantstull)lyintotwokinds.F'orexample,abigbridgepr('ducescrackbefolesapling.TIalisalsofoecasew'iththewciirofaxis,whichwilloccuronlywhenthelevelofweargetstoacertaillextent.TilesysteTllisrepairedwhenitoccursfllnctionfailure.Tosolvetheaboveproblem,itisnecessarytoextendthestateofplantandthemethodsofmo…     

Reliability‐based Optimal Maintenance Scheduling by Considering Maintenance Effect to Reduce Cost

A new reliability‐based optimal maintenance scheduling method is presented that considers the effect of maintenance in reducing costs. An ordering list of element maintenance effects with various maintenance‐interval types is constructed. By means of this ordering list, reliability‐based optimal maintenance scheduling for simple reliability structures and composite reliability systems is then carried out. The properties of the proposed method, such as the evaluation of maintenance cost reduction, the simplicity of the proposed method by sacrificing system availability within the allowance method, the operation decision based on the optimal maintenance schedule, etc., are discussed. With simulations, the effectiveness of the proposed method is verified. Copyright © 2005 John Wiley & Sons, Ltd.     

A Multi-agent Framework of an Integrated Plant Maintenance System

Based on systematic analysis, an Integrated Plant Maintenance System (IPMS) is proposed in this paper to cope with challenges in plant maintenance. The characteristics of the IPMS are summarized and the necessity of its modeling is set forth. Based on the analysis and comparison among structured,object-oriented and multi-agent modeling frameworks, a multi-agent modeling framework is selected in this paper as a theoretical guidance and together with the Tropos method for modeling, the system model of an integrated plant maintenance system is constructed. The system model developed in this paper provides a guidance template for the Baling company in its stepwise implementation of the IPMS.     

A Study on Maintenance Management and Maintenance Decision-Making Methods

By comparing the advantages and disadvantages of the main popular maintenance modes,this paper analyses the relationship between maintenance modes, and gives a model of maintenance decision-making. The model can be used in enterprises to minimize life cycle cost (LCC).     

面向状态维修的计划系统：维修的策略与战术规划

面向状态的维修策略有其优缺点。它带来经济上的效益，因为它延缓设备的磨损，并由于经常检查而提高了设备的利用率。其缺点则是对维修计划与控制的要求较高。战术规划的任务就是将维修策略付之实施，并将维修成本降至最低。     

Optimum Maintenance and Availability of Series Systems Subject to Imperfect Repair

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Maintenance Strategies and Failure‐Cost Model for Medical Equipment

This paper proposes a mathematical maintenance model that analyses the effect of maintenance on the survival probability of medical equipment based on maintenance history and age of the equipment. The proposed model is simulated in Scilab using real data extracted from maintenance history of anaesthesia machine from Draeger. The analysis using survival approach reveals that conducting preventive maintenance on the selected medical equipment had a positive impact on survival of equipment. The model is then used to analyse the cost of maintenance scenarios, and an appropriate scenario is proposed for anaesthesia machine. A new failure‐cost model is developed, which may be used to calculate the number of failures of equipment and the annual maintenance cost. The proposed models may be used as a planning tool for selecting maintenance strategies for various medical equipments. Copyright © 2014 John Wiley & Sons, Ltd.     

冲击环境下租赁设备预防维护策略优化研究

从租赁设备的工作环境出发,提出了一种基于冲击模型的故障建模方法,综合考虑改善因子与预防维护成本的制约关系以及租赁条件下的故障惩罚机制,建立了一种面向租赁设备的等周期预防维护策略,并以最小化期望总成本率为决策目标得到租赁设备的优化维护计划。算例分析显示,该策略符合一般租赁设备维护的实际情况,能为服务制造商提供有效的维护解决方案。     

核磁共振的典型故障维修三例

当前,核磁共振(MRI)技术日趋成熟,应用范围日益广泛,已经成为一项常规的医学检测手段。本文主要介绍了核磁共振设备的三个常见故障的现象及其维修方法等,以帮助读者更好地维持MRI系统的正常运行。     

虚拟维修中虚拟人的动作模型设计

提出了一种基于维修任务分解的虚拟人动作模型设计方法,将虚拟维修任务分解为三个过程,建立了三个相应的维修动作层次化模型,阐述了维修动作的分类与设计,并将维修动作模型应用到了虚拟维修过程中。实验结果表明,基于维修任务分解的虚拟人动作模型可以有效地将虚拟人技术应用到虚拟维修中,大大提高了虚拟维修的逼真性。     

民航视情维修决策优化模型发展

目前视情维修是民航业采用的主要维修方式，可以使维修的有效性、经济性大幅度提高。维修决策优化模型对民航维修成本的降低和利润的提升具有显著的指导作用；归纳了视情维修的时间延迟模型、冲击模型、比例危险模型、马尔可夫决策模型等优化模型的建模方法；分析了该类模型在应用中存在的不足，并展望了其发展前景。     

多部件系统机会维修优化模型

针对系统部件间存在经济相关性的情况,利用更新过程理论建立了机会维修策略下的多部件系统可靠性模型,并提出了求解系统期望维修费用率和稳态可用度的解析方法.在此基础上,以系统期望维修费用率最低为优化目标,稳态可用度满足要求为约束条件,通过非线性规划优化方法得到了系统的最佳机会维修阈值τ*.最后通过分析优化模型中不同变量与维修阈值之间的相互影响关系,讨论了不同维修策略的适用范围.     

可用度及动态维修成本下的维修决策模型

为了制定一个更具操作性、符合生产实际的设备维修计划,采用现代设备维修管理理论,考虑了预防维修成本的动态性,构建出一种以预防更新周期内单位时间总维修成本最小为优化目标,以设备可用度为约束条件的预防维修决策模型。通过引入算例,运用枚举法,借助Matlab仿真软件来验证模型的合理性,同时证明了企业可采用该种决策模型来实现其维修成本的最小化。     

Human Factors Effects and Analysis in Maintenance: A Power Plant Case Study

This paper proposes a methodical approach for identifying and reducing human error in maintenance activities, the human factors effect and analysis. Human factors effect and analysis presents a roadmap for selecting significant human factors affecting maintenance management as well as the most effective solutions using cost–benefit analysis. Safety and operational consequences of each human factor are compared to preventive and recovery risk controls to select the preferred risk control method. Because human factor programs are not implemented in many maintenance departments, quantitative data are rare. Thus, expert judgment may help to compare potential solutions. In order to show the applicability of the proposed approach a power plant in Kenya is selected as a case study. Procedure usage, fatigue, knowledge and experience, and time pressure are identified as the most important human factors. Training, task planning /shift management, knowledge management, scheduling as well as incident report programs are the most cost‐effective solutions for performing human factors program. The proposed approach would improve system reliability by recognizing human related failures. Furthermore, unexpected incident and accident may be reduced having knowledge about potential risk factors. Copyright © 2016 John Wiley & Sons, Ltd.     

面向环境的设备维护管理与再制造工程集成模式

在分析再制造工程与设备维护管理的理论体系及二者关系的基础上,从有效利用资源、提升设备的使用效能的角度出发,运用质量功能展开(Quality Function Display,简称QFD)方法,提出了一种面向环境需求的设备维护管理和再制造工程的集成模式。     

A study of availability-centered preventive maintenance for multi-component systems

This paper studies preventive maintenance (PM) in simultaneously considering three actions, mechanical service, repair and replacement for a multi-components system based on availability. Mechanical service denotes the activities including lubricating, cleaning, checking and adjusting, etc. which is set to alleviate strength degradation. Repair is defined on that not only slow down the degraded velocity but also restore the degraded strength partly. Replacement is settled to recover a component to its original condition. According to the definitions, the degradation of components is analyzed from its failure mechanisms and the improvements of various actions to it in reliability were measured by using two improved factors. Following the proposed model of reliability, the mean-up and mean-down times of each component are also investigated and the replacement intervals of components are determined based on availability maximization. Here, the minimum one among the intervals is chosen as the PM interval of system for programming the periodical PM policy. The selection of action for the components on every PM stage is decided by maximizing system benefit in maintenance. Repeatedly, the scheduling is progressed step by step and is terminated until the system extended life reaching to its expected life. The complete schedule provides the information, the actions adopted for the components, the availability and the total cost of system on each stage. Validly, a multi-components system is used as an example to describe the proposed algorithm.     

考虑缓冲区库存分配的并联系统预防维护策略研究

为提高并联系统生产过程的连续性,提出了考虑缓冲区库存分配的并联系统(3M1B)预防维护模型。首先,考虑并联系统每台设备的故障率与维护率,在并联系统中上下游设备之间建立缓冲区,构建3M1B系统。其次,考虑设备不完美生产的可能性,以缓冲区库存量与设备运行周期为决策变量,以设备最小生产成本率为目标函数建立预防维护模型,求解最佳的预防维护策略与缓冲区库存分配策略。针对此维护模型,采用离散迭代算法与遗传算法进行求解,并比较了2种算法的优劣,结果表明,对于此模型,离散迭代算法优于遗传算法。最后,通过算例验证模型的可行性和有效性。     

Modeling and Analysis of Complex Equipment Maintenance Dynamics

An equipment maintenance system is naturally a complex dynamical system. The effective mamanagement must be based on the knowledge of the system＇s intrinsic dynamics. And the strueture of the maintenance system determines its behavior. This paper analyzes the basic structures and elements of a maintenance system for complex multi-components equipment. The maintenance system is considered as a dynamic system whose behavior is influenced by its structure＇s feedback and interaction, and the system＇s available resources. Building the dynamical model with Simulink, we show some results about the maintenance system＇s nonlinear dynamics, ods. The model can be used for understanding and which operational adjustments of maintenance which are never given by stochastic process methdetermining maintenance system behavior, towards n of maintenance requirements and timely supply of maintenance resources can be made in a more informed way.     

A Dynamic Risk Assessment Methodology for Maintenance Decision Support

The failure mode and effect analysis (FMEA) is a widely applied technique for prioritizing equipment failures in the maintenance decision‐making domain. Recent improvements on the FMEA have largely focussed on addressing the shortcomings of the conventional FMEA of which the risk priority number is incorporated as a measure for prioritizing failure modes. In this regard, considerable research effort has been directed towards addressing uncertainties associated with the risk priority number metrics, that is occurrence, severity and detection. Despite these improvements, assigning these metrics remains largely subjective and mostly relies on expert elicitations, more so in instances where empirical data are sparse. Moreover, the FMEA results remain static and are seldom updated with the availability of new failure information. In this paper, a dynamic risk assessment methodology is proposed and based on the hierarchical Bayes theory. In the methodology, posterior distribution functions are derived for risk metrics associated with equipment failure of which the posterior function combines both prior functions elicited from experts and observed evidences based on empirical data. Thereafter, the posterior functions are incorporated as input to a Monte Carlo simulation model from which the expected cost of failure is generated and failure modes prioritized on this basis. A decision scheme for selecting appropriate maintenance strategy is proposed, and its applicability is demonstrated in the case study of thermal power plant equipment failures. Copyright © 2016 John Wiley & Sons, Ltd.     

A Functional Inspection Model for the Immeasurable Potential Failure State

Functional inspection is a type of preventive maintenance of Reliability Centered Maintenance(RCM). We, in this paper, establish a functional inspection model(FIM)——the cost model and the availability model for the immeasurable potential failure state based on the delay time concept. This model can be used to determine the appropriate Functional Inspection Interval(FII) to achieve the goal of specific cost and availability and to assist in maintenance decision making.