Comprehensive framework for underground pipeline management with reliability and cost factors using Monte Carlo simulation

A reliability model for underground pipeline management that can quantify the trade-off between risk reduction and increased maintenance costs in various underground piping management scenarios can be useful for many pipeline-maintenance decision-makers. In this paper, we propose a comprehensive framework for analyzing underground pipeline management options. Pipeline reliability is calculated using time-dependent and independent limit state functions with a probabilistic model and a deterministic model about the frequency of a failure occurrence event. The proposed framework includes the target reliability, consequences, and cost model, and has the advantage that it can be intuitively utilized for piping management decision-making. We conducted several case studies using a Monte Carlo simulation on pipelines in industrial complexes in Korea.     

A novel tool for Bayesian reliability analysis using AHP as a framework for prior elicitation

Quantitative risk assessment (QRA) is a powerful and popular technique to support risk-based decisions. Unfortunately, QRAs are often hampered by significant uncertainty in the frequency of failure estimation for physical assets. This uncertainty is largely due to lack of quality failure data in published sources. The failure data may be limited, incompatible and/or outdated. Consequently, there is a need for robust methods and tools that can incorporate all available information to facilitate reliability analysis of critical assets such as pipelines, pressure vessels, rotating equipment, etc. This paper presents a novel practical approach that can be used to help overcome data scarcity issues in reliability analysis. A Bayesian framework is implemented to cohesively integrate objective data with expert opinion with the aim toward deriving time to failure distributions for physical assets. The Analytic Hierarchy Process is utilized to aggregate time to failure estimates from multiple experts to minimize biases and address inconsistencies in their estimates. These estimates are summarized in the form of informative priors that are implemented in a Bayesian update procedure for the Weibull distribution. The flexibility of the proposed methodology allows for efficiently dealing with data limitations. Application of the proposed approach is illustrated using a case study.     

A framework for human error risk analysis of coal mine emergency evacuation in China

Evacuation from underground coal mine in emergency as soon as possible makes the difference between life and death. Human factors have an important impact on a successful evacuation, but literature review shows that there is a lack of consideration of human error risk during coal mine emergency evacuation in China. To address the above problems, in this paper, we established a framework for human error risk analysis of coal mine emergency evacuation, consisting of scenario and task analysis, risk assessment and risk reduction. A general evacuation procedure which is applicable for different causes is detailed through the scenario and task analysis. A new method based on expert judgment, named OGI-Model, is proposed to evaluate the reliability of human safety barrier. In this new approach, human safety barrier is divided into three sub-barriers, i.e., organization safety sub-barrier (OSSB), group safety sub-barrier (GSSB), and individual safety sub-barrier (ISSB). Each sub-barrier consists of a series of concrete measures against specific evacuation actions. An example is provided in this paper to demonstrate the use of this framework and its effectiveness.     

应急撤离建模研究的现状、问题与发展趋势

分析以往的突发事件应急撤离决策过多依赖决策者主观判断的问题,提出通过构建应急撤离模型为决策者提供更客观的辅助决策信息,并阐述了应急撤离建模过程涉及的主要要素。通过对3种主要应急撤离建模方法——宏观、微观和中观的撤离建模过程的详细介绍和分析,综观了当前应急撤离建模的研究现状。在该基础上,研讨每种建模方法的特点、适用范围以及存在的主要问题,并针对这些问题,给出可能的解决方法和未来的发展方向。归纳应急撤离建模研究的成果,提出在实际应急撤离建模工作中应注意的问题。     

船舶溢油应急反应人的可靠性分析研究

为减小船舶溢油事故应急反应人员失误概率,提升应急处置效果,在对应急人员可靠性主要影响因素识别的基础上,利用模糊贝叶斯网络(BN)建立船舶溢油应急人的可靠性分析(HRA)模型,将应急反应流程抽象为可进行概率推算的BN,实现单个应急任务和全过程人的可靠性的量化评估,并依据该模型对一起船舶溢油事故进行实例研究。结果表明,首先模糊集值专家评估较好地解决应急人员可靠性情境依赖性强,难以量化评估的问题;其次,BN卓越的概率推理性能实现由单个应急任务向全过程人的可靠性的推算;最后得到应急反应人的可靠性主要取决于关键应急任务的完成情况和相关情境因素的影响。     

面向网络的过程工业安全与可靠性分析及实现

根据过程工业安全与可靠性的特点,介绍过程工业几种典型的安全分析与评价方法,建立过程工业的系统可靠性模型和基于Bayes方法的可靠性评价方法。通过收集工业现场的信息,进行安全与可靠性的预评估,建立模型与进行分析,预测后果与评估。过程工业的安全与可靠性分析和评价过程需要处理大量的现场数据信息以及完成复杂的计算,利用工业控制网络,基于B/S与C/S相结合的网络体系结构,提出面向网络的过程工业安全与可靠性模型。运用该模型,构建一个应用于过程工业的安全与可靠性分析与评价系统,描述系统实现的主要功能,该系统的实现是过程工业在安全与可靠性领域开展数字化维护的实际应用。     

城市公共安全系统可靠性研究

城市公共安全体系由诸多子系统组成 ,其功能的实现依赖于城市公共安全系统的整体可靠性。笔者采用组合功能分析和过程分解的方法 ,对城市公共安全系统的功能、结构和组成进行了讨论 ;应用结构化功能-事件树的混合方法对城市公共安全系统的可靠性特征进行了定性分析 ;建立了城市公共安全系统可靠性模型 ,相应的数学模型可作为城市公共安全保障工作中预防为主的科学依据。据此可以得出 :城市公共安全系统中事故和灾害预防子系统的地位应优于事故预警、应急反应和灾害控制等后处理环节的结论 ,同时可以给出了城市规划中公共安全系统设计的建议。     

我国自然灾害类应急预案评价方法研究(Ⅲ):可操作性评价

从预案执行人员的角度出发,将可操作性评价转化为复杂性评价,并以国家地震应急预案为例,构建针对应急预案结构的可操作性评价方法。该方法由3步完成:首先,应急预案具有由描述性语言组成的特点,分析国内现有应急预案的组织结构,采用语句成分分析的方法对预案中的关键信息和行动进行提取与处置;然后,引入软件工程中的程序流转图,将描述性的预案文本转换为包含行动以及它们之间逻辑与层次关系的结构控制图;最后,借鉴度量软件复杂性的方法,定义了结构控制图的内部复杂度和综合复杂度等一系列指标,用于应急预案的复杂性即可操作性评价。评价结果可为完善和修订应急预案提供科学依据。     

基于信息共享的突发事件应急响应信息模型(Ⅱ):模型计算

以数字城市服务平台为支撑,构建一个面向突发事件应急的决策框架系统,以解决应急响应信息模型计算涉及的3个关键问题:分布数据的获取、应急辅助模型的运算和应急响应辅助数据集的分发。系统利用平台的服务总线来获取分布的部门数据资源,并分发信息模型计算得到的数据集,使用平台的模型库系统来管理和调度应急辅助模型,通过模板机制实现信息模型的快速定义和重用,并提供一个基于W eb的事件报送接口来实时接收事件信息。将系统运用于前文构建的突发化学品事故信息模型的计算中,过程表明,系统可完成模型计算的任务,并能够扩展到其他的突发事件应急中。     

基于Isograph的地铁车载ATP系统动态故障树分析

针对传统的可靠性分析方法在具有动态特性的地铁车载ATP系统可靠性分析中的不足,提出动态故障树分析法。在引用可用度、平均失效时间和平均修复时间等可靠性指标的基础上,结合Isograph软件改进动态故障树分析法,建立基于Isograph的动态故障树分析模型,并通过对车载ATP系统的结构与功能分析以及历史故障数据的统计分析确定车载ATP系统的关键部件,使用 Isograph软件预计关键部件的可靠性参数,对地铁车载ATP系统的可靠性进行评估。结果表明:采用该方法求解的系统可靠性指标均满足系统需求,并且精确度较高,运用此方法能够对具有顺序相关、资源共享、可修复以及冷、热备份等特性的系统进行可靠性建模,达到快速以及准确分析动态特性系统可靠性的目的。     

应急决策的理论与方法探讨

围绕基于模板的规划、组织决策协调与基于Agent系统的协调机制以及马尔可夫决策规划等应急决策的关键理论与方法,对国内外相关研究进行分析与总结;提出以决策理论规划为应急决策研究的主要建模和分析框架;采用逻辑程序与规划相结合的思想,研究基于应急预案模板的应急决策规划方法;基于应急处置任务的时间、资源约束关系,研究应急处置任务的多Agent马尔可夫决策建模及求解方法。基于决策理论规划的应急决策理论可以很好地用于应急决策的多阶段动态过程建模,而且能够利用预案模板降低模型求解的难度。上述研究完善和丰富了应急决策的理论和方法,为科学的应急决策实践以及应急决策支持系统提供了一种理论和方法。     

Issues of the Human Reliability Analysis in the Context of Probabilistic Safety Studies

This article addresses methodological issues of the human reliability analysis (HRA) in the context of probabilistic safety studies. Several conventional HRA techniques, more often used for the evaluation of the human error probabilities (HEPs), have been classified. A taxonomy of human actions, failure events, and related factors is outlined in order to distinguish action phases, human behavior types and incorrect outputs (errors of omission or commission), error types (slips, lapses, and mistakes), and performance-shaping factors (PSFs) influencing the human performance. A tree is proposed to facilitate the selection of a specific method for the evaluation of human reliability with regard to attributes of the situation analyzed. A software system based on the expert system technology to facilitate and document PSA and HRA is outlined. At the end of the article some research challenges in the domain are discussed.     

信效度在安全生产标准化元评估中的应用研究

安全生产标准化评审是根据一定的安全生产标准化评审目标和标准,通过系统地收集信息和科学分析,对企业安全生产标准化工作做出价值判断的过程。为了科学评估评审偏差和统一评审尺度,基于信效度理论,提出在评审单位和评审组织单位进行安全生产标准化元评估时,应用评审者信度和效标关联效度,研究安全生产标准化评审的可靠程度和有效程度;并以危险化学品从业单位安全生产标准化评审为例,从信效度的分析方法选择、信效度的计算和信效度的可接受度,全面探究信效度在安全生产标准化元评估中的实现方式。结果表明,应用信效度方法分析安全生产标准化评审的优势和不足,可以为安全生产标准化评审结果的客观评价提供依据。     

A taxonomy of performance influencing factors for human reliability analysis of emergency tasks

This paper introduces the process for, and the result of, the selection of performance influencing factors (PIFs) for the use in human reliability analysis (HRA) of emergency tasks in nuclear power plants. The approach taken in this study largely consists of three steps. First, a full-set PIF system is constructed from the collection and review of existing PIF taxonomies. Secondly, PIF candidates are selected from the full-set PIF system, considering the major characteristics of emergency situations and the basic criteria of PIF for use in HRA. Finally, a set of PIFs is established by structuring representative PIFs and their detailed subitems from the candidates. As a result, a set of PIFs comprised of the 11 representative PIFs and 39 subitems was developed.     

随机桁架结构可靠性分析的完全概率方法

提出了一种求解随机参数桁架结构在随机荷载作用下反应的概率密度函数和结构精确可靠度的方法.通过对随机参数桁架结构在随机荷载作用下的有限元分析方法的研究,考虑了结构的物理参数,构件的几何尺寸和作用荷载幅值等的随机性.应用随机向量函数的概率分布函数表达式,通过确定积分区间、变量替换、交换积分顺序等一系列数学上的处理,获得所求结构反应的概率密度函数.由干涉理论得到了结构位移和应力的可靠度.通过算例的结果与Monte-Carlo模拟法结果比较,表明该方法具有较高的精度及良好的实用性.     

安全系统可靠性分析方法

讨论了安全系统可靠性分析的最新趋势,即:由对系统的定性分析转向定量分析.给出了可靠性分析的一些方法,包括定性和定量方法.重点研究了马尔可夫故障模型法.针对马尔可夫故障模型法计算量大的缺点,提出了相应的改进方法微马尔可夫故障模型法,分析了此法在可靠性分析中的应用.     

应急响应逻辑流程构建及其应用研究

针对目前部分预案中的应急响应存在上下一致、缺乏操作性以及存在区域盲点等问题,提出基于应急响应行动及区域灾害后果的分析构建应急响应逻辑流程。其中分层的应急行动结构体现了不同级别预案应急响应的侧重与分工,承灾体状态与应急任务关联的建立使应急响应流程更适应事件发生区域灾害后果。提出的应急响应逻辑流程是针对不同区域不同事件的应急响应流程通用的建模方法,可作为区域发生某事件所启动预案的应急响应评估模板,为修订和完善应急预案提供参考依据。     

Applications of fuzzy faulty tree analysis and expert elicitation for evaluation of risks in LPG refuelling station

A method is presented for analysis of reliability of complex engineering systems using information from fault tree analysis and uncertainty/imprecision of data. Fuzzy logic is a mathematical tool to model inaccuracy and uncertainty of the real world and human thinking. The method can address subjective, qualitative, and quantitative uncertainties involving risk analysis. Risk analysis with all the inherent uncertainties is a prime candidate for Fuzzy Logic application. Fuzzy logic combined with expert elicitation is employed in order to deal with vagueness of the data, to effectively generate basic event failure probabilities without reliance on quantitative historical failure data through qualitative data processing.The proposed model is able to quantify the fault tree of LPG refuelling facility in the absence or existence of data. This paper also illustrates the use of importance measures in sensitivity analysis. The result demonstrates that the approach is an apposite for the probabilistic reliability approach when quantitative historical failure data are unavailable. The research results can help professionals to decide whether and where to take preventive or corrective actions and help informed decision-making in the risk management process.     

基于云模型的海上船舶溢油应急管理能力评估方法

为更好地解决海上船舶溢油应急管理能力评估过程中的不确定性问题，提出1种基于区间二型模糊层次分析法的云模型综合评估方法。针对评估体系的局部性，借鉴PPRR应急管理过程理论，对影响船舶溢油应急管理能力的因素进行分级和分类，构建全局评估指标体系；分别运用区间二型模糊层次分析法和逆向云发生器确定各指标权重和云模型参数；通过浮动云和综合云算法获得最终评估结果。结果表明:将5个评估等级和评估结果进行仿真得出评估云的“云滴”图可显示出评估结果的能力等级以及评估结果的可信度和稳定性。计算某海区船舶溢油应急管理能力的评估等级为“较好”，即管辖该海区的海事管理部门能较好地解决海上船舶溢油突发事故，验证了所提方法的可行性和有效性。     

Mitigation of operational failures via an economic framework of reliability,availability, and maintainability (RAM) during conceptual design

Abnormal process situation may lead to tremendous negative impact on sustainability, wellbeing of workers and adjacent communities, company's profit, and stability of supply chains. Failure of equipment and process subsystems are among the primary causes of abnormal situations. The conventional approach in handling failure-based abnormal situations has usually focused on operational strategies. Such an approach overlooks the critical role of process design in mitigating failure, while simultaneously considering the effects of such failure on process economic performance. The aim of this work is to introduce a systematic methodology that accounts for failure early enough during the conceptual design stages. Once a base-case design is developed, the methodology starts by identifying the sources of failure that are caused by reliability issues including equipment, operational procedures, and human errors for a given process system or subsystem. This allows for the identification of critical process subsystem(s) that are more failure-prone or cause greater downtime than other subsystems. Bayesian updating and Monte Carlo techniques are utilized to determine the appropriate distributions for the failure and repair scenario(s), respectively, in question. Markov analysis is used to determine the system availability. Next, the process revenue is described as a function of inherent availability. The effects of failures are incorporated into profitability calculations to establish an economic framework for trading off failure and profitability. In the proposed framework, the economic potential of alternative design scenarios is evaluated and an optimization formulation with the objective of maximizing incremental return on investment (IROI) is utilized to make a design decision. A case study on an ethylene plant is solved to demonstrate the applicability and value of the proposed approach.