Reliability estimation based on operational data of manufacturing systems

Maintenance management has a direct influence on equipment reliability and safety. However, a large portion of traditional maintenance models and reliability analysis methods usually assumes that only perfect maintenance is performed on the system and the system will restore to as good as new regardless of the kind of preventive maintenance work‐order that is performed. This is not practical in reality and may result in an inaccurate parametric estimation. The research objective of this paper is to develop a maximum likelihood estimation method to obtain more accurately estimated parameters based on the operational data of manufacturing systems, taking into consideration the difference between perfect and imperfect maintenance work‐orders. Weibull distribution is specifically studied for this purpose. A practical case study based on industrial operational data from an automotive assembly line is performed to illustrate the implementation and efficiency of the proposed reliability estimation method. Copyright © 2008 John Wiley & Sons, Ltd.     

IEC 61511 and the capital project process--a protective management system approach

This year, the process industry has reached an important milestone in process safety-the acceptance of an internationally recognized standard for safety instrumented systems (SIS). This standard, IEC 61511, documents good engineering practice for the assessment, design, operation, maintenance, and management of SISs. The foundation of the standard is established by several requirements in Part 1, Clauses 5-7, which cover the development of a management system aimed at ensuring that functional safety is achieved. The management system includes a quality assurance process for the entire SIS lifecycle, requiring the development of procedures, identification of resources and acquisition of tools. For maximum benefit, the deliverables and quality control checks required by the standard should be integrated into the capital project process, addressing safety, environmental, plant productivity, and asset protection. Industry has become inundated with a multitude of programs focusing on safety, quality, and cost performance. This paper introduces a protective management system, which builds upon the work process identified in IEC 61511. Typical capital project phases are integrated with the management system to yield one comprehensive program to efficiently manage process risk. Finally, the paper highlights areas where internal practices or guidelines should be developed to improve program performance and cost effectiveness.     

Age-dependent reliability model considering effects of maintenance and working conditions

Nowadays, there is some doubt about building new nuclear power plants (NPPs). Instead, there is a growing interest in analyzing the possibility to extend current NPP operation, where life management programs play an important role. The evolution of the NPP safety depends on the evolution of the reliability of its safety components, which, in turn, is a function of their age along the NPP operational life. In this paper, a new age-dependent reliability model is presented, which includes parameters related to surveillance and maintenance effectiveness and working conditions of the equipment, both environmental and operational. This model may be used to support NPP life management and life extension programs, by improving or optimizing surveillance and maintenance tasks using risk and cost models based on such an age-dependent reliability model. The results of the sensitivity study in the example application show that the selection of the most appropriate maintenance strategy would directly depend on the previous parameters. Then, very important differences are expected to appear under certain circumstances, particularly, in comparison with other models that do not consider maintenance effectiveness and working conditions simultaneously.     

Reliability analysis for socio-technical system,case propene pumping

Reliability is not a specified study for each functional part of the industry, isolated one from other. The reliability of each part is interconnected with each other and their level of integration depends on the level of automation, type of process, management style, and organizational environment. By understanding on relations between the functions of these systems becomes possible to study the integrated reliability. This knowledge allows the formatting of factors that increase the performance of staff and of equipment leading to greater organizational efficiency. This work aims to clarify how the different reliabilities communicate with each other, and how to establish integrated programs without excessive resources for deployment and management of integrated reliability. A new management type and organizational environments are proposed to transform people and equipment even more reliable to the system. In this moment we are proposing new techniques to analyze the failure, the accident, the task, and the hazards. The task analysis allows the integration between the operation and the worker that, in consequence, becoming more reliable. The design of process control allows maintenance of process capability in response to operational actions. The reliability and the maintainability of equipment depend on the level of automation and confidence in the project work. A good tool to interface man–machine integrates the human and the equipment, increasing the reliability system. The skills to perform a well-designed task (operational reliability) keep the equipment under control. The knowledge of the operator ensures that processes are been controlled and are able to meet their goals. The success of integration of the reliabilities is ensured and achieved with the adoption of new organizational patterns and new management styles. Thus it becomes possible to transform policy into practice without having divergent values or reduce conflict between priorities in the areas of safety and production.     

维修管理模式对制造企业质量控制影响的实证研究

可靠的设备预防维修水平和卓越的产品质量保证能力是保障产品过程质量的关键,现有多数研究集中在质量管理模式与企业绩效的关系分析。在对过程质量控制、设备维修管理评述的基础上,探讨了设备维修管理模式与维修绩效及过程质量控制绩效间的关系。以国内制造企业的连续生产方式为研究对象,运用结构方程模型剖析了RCM、TPM、设备采购管理与和设备维修绩效、过程质量控制绩效的路径关系,发现基础维修管理活动对维修绩效有间接影响,RCM、TPM对设备维修绩效有显著影响,路径系数分别为0.346、0.717,设备维修绩效对过程质量控制绩效的影响显著,路径系数为0922。证明制造企业为提升产品质量,需要完善其设备预防维修系统。     

Effective Safety Management: a Case Study in the Chemical Industry

A major non‐trivial problem within the area of industrial safety management today is to analyse, next to the safety impact of the technical equipment, the safety impact of a ‘business process’ as currently required by regulation and safety standards. This paper describes a case study of a pesticide company struggling with the question of how to improve the safety of their operational process further and at the same time also improve the reliability of their operational process. According to the literature ‘control of the business process’ is the keyword to improve the safety and reliability ‘performance’ of a company. A formal control model is proposed together with a classification system (using maturity levels) to analyse and qualify business processes with respect to their impact on process safety. This method has been applied in a case study where it resulted in a model of a business process. Using the model it was possible to classify the business process control system used and to identify related improvement opportunities. The proposed method showed that, in contrast to the company's perception, it was not the production department that was responsible for most of the problems but the peripheral processes relating to the production department. The interaction between departments caused not only potential safety problems, but also caused system reliability problems. For the company it was demonstrated that the interdependency of the (different activities in the‐) operational process is an essential element preventing further improvement if not addressed properly. Copyright © 2004 John Wiley & Sons, Ltd.     

维修工程管理研究与发展综述

综述了近几十年来维修工程管理的研究与发展，如人工智能、故障诊断、机器状态监测技术(如振动分析、红外检测、热录像仪等)、预测和预防性维修(PPM)、全员生产维修(TPM)和主动性维修(PM)等，论述了综合应用机器实时状态监测与故障诊断、人工智能、计算机通讯技术以及先进的维修管理理念的集成质量控制与维修系统，最后提出一种目前世界领先的远程智能维修系统。内容包括：实践应用中的维修管理评估、智能和集成维修管理、状态监测维修中的智能预测决策支持系统(IPDSS)、设备状况衰退趋势预测——人工神经网络方法、IPDSS支持的维修管理、故障诊断中的人工智能应用、基于可靠性的预防性维修安排和远程智能维修系统。     

Time-dependent reliability analysis of flood defences

This paper describes the underlying theory and a practical process for establishing time-dependent reliability models for components in a realistic and complex flood defence system. Though time-dependent reliability models have been applied frequently in, for example, the offshore, structural safety and nuclear industry, application in the safety-critical field of flood defence has to date been limited. The modelling methodology involves identifying relevant variables and processes, characterisation of those processes in appropriate mathematical terms, numerical implementation, parameter estimation and prediction. A combination of stochastic, hierarchical and parametric processes is employed. The approach is demonstrated for selected deterioration mechanisms in the context of a flood defence system. The paper demonstrates that this structured methodology enables the definition of credible statistical models for time-dependence of flood defences in data scarce situations. In the application of those models one of the main findings is that the time variability in the deterioration process tends to be governed the time-dependence of one or a small number of critical attributes. It is demonstrated how the need for further data collection depends upon the relevance of the time-dependence in the performance of the flood defence system.     

A review of condition-based maintenance: Its prognostic and operational aspects

Condition-based maintenance (CBM) detects early signs of failure and dictates when maintenance should be performed based on the actual condition of a system. In this paper, we first review some of the recent research on CBM under various physical structures and signal data. Then, we summarize several kinds of prognostic models that use monitoring information to estimate the reliability of complex systems or products. Monitoring information also facilitates operational decisions in production planning, spare parts management, reliability improvement, and prognostics and health management. Finally, we suggest some research opportunities for the reliability and operations management communities to fill the research gap between these two fields.     

Improving aircraft safety and reliability by aircraft maintenance technician training

Aircraft maintenance is one of the primary causes or contributing factors in aircraft accidents. It is clear that proper training of Aircraft Maintenance Technicians (AMTs) will avoid failures, reduce maintenance related accidents, improve safety and reliability in aviation and provide recovery of the increasing demand to qualified AMTs for sustainability of the market growth. In this study, European Safety Agency (EASA) based AMT licencing system in EU states (and non-EU states implementing EASA rules) has been analysed and a training model developed in accordance with EASA Part-66 requirements and delivered by e-learning methods has been introduced. The analysis of the licensing process based on EASA regulations showed that this process was based on the candidate's demonstration of knowledge and acquisition of experience. The required experience depends on the training background of the candidate. Field exercise showed that developed e-learning training model, which overcomes the disadvantages of traditional face to face training models, succeeded to improve the attendees' theoretical knowledge level and when combined with the practical trainings given to AMT candidates in maintenance organisations during their experience periods, will be very successful in improving safety and reliability in aviation maintenance operations.     

Examination of issues related to the development and implementation of real-time operational safety monitoring tools in the nuclear power industry

In recent years, risk and reliability techniques have been increasingly used to optimize deterministic requirements and to improve the operational safety of nuclear power stations. This paper discusses the historical development and current status of implementation of real-time operational safety monitoring tools in the nuclear power industry worldwide. A safety monitor is defined as a PC-based risk management tool, based on a plant specific PSA, which can be used to manage plant safety during the day-to-day operation of a nuclear power plant by planning maintenance activities and providing advisory information to plant operational staff in order to avoid high risk plant configurations. As this technique has only been applied in a few plants worldwide, the technology is still evolving and there are several technical and implementation-related issues which still need to be resolved. This paper attempts to summarize all such issues and describe how they have been addressed in several different applications of this technology around the world.     

Corrective maintenance through dynamic work allocation and pre-emption: case study and application

This case study develops an innovative management and scheduling system for corrective maintenance of machines in a manufacturing facility. The study also involves a comparative evaluation of the proposed and the existing systems under a spectrum of operating conditions. A comprehensive simulation is used to evaluate system performances under a variety of settings which include reliability, service level, and cost consequences. The analysis is based on a full factorial experimental design. In summary, the developed self-regulating management system which involves dynamic work allocation and pre-emption is shown to yield higher machine availability and higher mechanic utilisation even with fewer mechanics. The study also finds that the new system is more streamlined, agile, and robust although it is subject to more-constrained machine reliability and mechanic service time environments. Further, a major reduction of current manpower can still achieve at least 95% machine availability, illustrating the cost effectiveness and efficacy of the developed system. This rule-based corrective maintenance system can be operated in uncertain environments on a real-time basis without additional reformatting costs and provides a competitive measure to deal with managerial issues such as low retention rate for skilled mechanics, highly uneven training levels and pay scales. The financial consequences and gains in strategic advantage with respect to the facility's operational structure are promising after implementation. Moreover, the system developed in this case study represents a meaningful starting point for a more vigorous theoretical research on the bucket brigade system to different functions in industrial and operations management.     

Infrastructure Communication Sensitivity Analysis of Wireless Sensor Networks

Sensitivity or importance analysis has been widely used for identifying system weaknesses and supporting system improvement and maintenance activities. Despite the rich literature on the sensitivity analysis of many mission‐critical and safety‐critical systems, no existing work has been devoted to wireless sensor networks (WSN). In this paper, we first analyze link and node importance with respect to the infrastructure communication reliability of WSN systems. The binary decision diagrams based algorithms are implemented to evaluate and compare three importance measures: structural importance measure, Birnbaum's measure, and criticality importance measure. The effects of node degree, choice of the destination node, data delivery models, as well as mission time on the importance analysis results are investigated through examples. Results from this work can facilitate the design, deployment, and maintenance of reliable WSN for critical applications. Copyright © 2015 John Wiley & Sons, Ltd.     

Complex system reliability modelling with Dynamic Object Oriented Bayesian Networks (DOOBN)

Nowadays, the complex manufacturing processes have to be dynamically modelled and controlled to optimise the diagnosis and the maintenance policies. This article presents a methodology that will help developing Dynamic Object Oriented Bayesian Networks (DOOBNs) to formalise such complex dynamic models. The goal is to have a general reliability evaluation of a manufacturing process, from its implementation to its operating phase. The added value of this formalisation methodology consists in using the a priori knowledge of both the system's functioning and malfunctioning. Networks are built on principles of adaptability and integrate uncertainties on the relationships between causes and effects. Thus, the purpose is to evaluate, in terms of reliability, the impact of several decisions on the maintenance of the system. This methodology has been tested, in an industrial context, to model the reliability of a water (immersion) heater system.     

Complex system reliability modelling with Dynamic Object Oriented Bayesian Networks (DOOBN)

Nowadays, the complex manufacturing processes have to be dynamically modelled and controlled to optimise the diagnosis and the maintenance policies. This article presents a methodology that will help developing Dynamic Object Oriented Bayesian Networks (DOOBNs) to formalise such complex dynamic models. The goal is to have a general reliability evaluation of a manufacturing process, from its implementation to its operating phase. The added value of this formalisation methodology consists in using the a priori knowledge of both the system's functioning and malfunctioning. Networks are built on principles of adaptability and integrate uncertainties on the relationships between causes and effects. Thus, the purpose is to evaluate, in terms of reliability, the impact of several decisions on the maintenance of the system. This methodology has been tested, in an industrial context, to model the reliability of a water (immersion) heater system.     

无损检测技术评估和检测道路性能

目前,在我国的基础设施管理方面,存在维修工作安排不当、养护维修不及时、维修预算支出庞大等问题。因此,为了保障道路安全,防止发生灾难性的破坏,需要采取快速、有效的养护管理方法,以提高道路的使用寿命。根据美国材料与试验协会(ASTM)路面状况评价标准,本文介绍了五种道路无损检测技术和设备:落锤式弯沉仪、探地雷达、宏观构造深度、国际平整度指数和面波的频谱分析,并分别介绍了每种检测技术的工作原理和运用方法,以指导相关人员结合实际合理选用。运用这几种检测方法将会在不封闭交通的情况下加快评估速度,并为搭建一个高效、智能的路网监测系统提供技术支持,为道路的可持续发展、资金的高效利用提供切实可行的方法。     

Invited paper Perspectives and challenges for research in quality and reliability engineering

In this paper we present some of the recent advances in the quality and reliability engineering methodologies. These advances include change point detection, monitoring processes with correlated observations, monitoring and control of multivariate processes, integration of the statistical process control with engineering process control, accelerated life testing, degradation models, predictive maintenance, and software reliability engineering. Future directions of research in quality and reliability engineering and their challenges are also discussed.     

民用爆炸物品使用现场的安全管理

加强民用爆炸物品使用现场的安全管理 ,有利于维护政治稳定、治安稳定 ,有效预防和杜绝涉爆违法、违规案件和事故的发生。本文从加强领导的安全意识和管理职能、落实安全生产责任制、加强从业人员的安全教育和综合素质培养、健全施工现场爆炸物品管理制度、完善施工现场的监督和检查机制、必要的安全管理资金和设施的投入等六个方面论述了加强用民爆炸物品使用现场安全管理的必要性。     

民用爆炸物品使用现场的安全管理

加强民用爆炸物品使用现场的安全管理 ,有利于维护政治稳定、治安稳定 ,有效预防和杜绝涉爆违法、违规案件和事故的发生。本文从加强领导的安全意识和管理职能、落实安全生产责任制、加强从业人员的安全教育和综合素质培养、健全施工现场爆炸物品管理制度、完善施工现场的监督和检查机制、必要的安全管理资金和设施的投入等六个方面论述了加强用民爆炸物品使用现场安全管理的必要性。