户外端子箱操作人因可靠性及其风险评价

为正确评价人为因素对户外端子箱失效的影响,利用CREAM(Cognitive Reliability and Error Analysis Method)模型的共同绩效条件分析端子箱操作过程中人的行为机理以及行为可靠性因素;应用SLIM(Success Likelihood Index Method)模型计算人为失误概...     

Human error analysis in furnace start-up operation using HEART under intuitionistic fuzzy environment

To address human error in system reliability, Human Reliability Analysis (HRA) is an essential issue. Human Error Assessment and Reduction Technique (HEART) as a rather straightforward technique for HRA has successfully been used in many areas to predict human error probability (HEP). However, knowledge acquisition of experts during assessed proportion of affect (APOA) calculation is subjected to vagueness and ambiguity. To overcome this challenge, in this paper Intuitionistic Fuzzy (IF) set due to their advantage to represent more fuzzy information than a classical fuzzy set adopted through APOA calculation. To demonstrate this hybrid approach short for, IF-HEART, the furnace start-up operation is handled, since analysis shows that most of explosions and losses occur during furnace start-ups operation. Further, a sensitivity analysis is carried out to approve the proposed integrated approach. In addition to its academic contribution, the results of the paper enable to improve the overall safety level of a furnace by taking into account potential human error.     

危险品集装箱堆场人因失误概率量化方法研究

由于人因失误是引发危险品集装箱堆场事故的主要原因,特别以成功似然指数法为框架研究了危险品集装箱堆场人因失误概率的量化方法。考虑了影响因子的主观特性,重点结合认知可靠性与失误分析方法对成功似然指数法进行修正,确定了培养与组织管理、同时出现的目标数量等6项行为形成因子。通过建立熵权法、模糊集合理论与专家判断的融合实现人因失误概率的计算。最后,用算例验证了方法的有效性,结果表明,本方法不但可将测算精度控制在有效区间(0,0.059 5),而且相较其他方法将危险系数降低了6.97%。针对危险品集装箱堆场管理这类高危行业,较高的人因失误率有利于风险辨识和风险预防。     

Determination of human error probabilities in maintenance procedures of a pump

The “human factor” constitutes an important role in the prediction of safe operation of a facility. Hence, information about human capacities and behaviours should be applied methodically to increase the safety of a systematic process. This paper provides an analysis of human factors in pre- and post-maintenance operations. For possible failure scenarios, this paper considers the procedures for removing process equipment from service (pre-maintenance) and returning the component to service (post-maintenance). In this study, a pump is used as the test example. For each scenario, the human error probability (HEP) is calculated for each activity, using the Human Error Assessment and Reduction Technique (HEART) which is commonly implemented technique in industry, can also be applied in the analyses of safety cases. HEART is a reliable technique for comparing HEP and its approach is based on the degree of error recovery. Consequences are also assessed for each activity in this methodology. The final value of risk for each activity is assigned by combining error likelihood and related consequences. When the calculated risk is beyond acceptable levels, risk management strategies are provided to increase the safety of the maintenance procedures. The most probable human errors for a considered case study are related to the activities of “draining lines” and “open valves”. These two activities have high HEPs, which are 9.57E−01 and 9.62E−01, respectively.     

Determination of human error probabilities for offshore platform musters

The focus of this work is on prediction of human error probabilities during the process of emergency musters on offshore oil and gas production platforms. Due to a lack of human error databases, and in particular human error data for offshore platform musters, an expert judgment technique, the Success Likelihood Index Methodology (SLIM), was adopted as a vehicle to predict human error probabilities. Three muster scenarios of varying severity (man overboard, gas release, and fire and explosion) were studied in detail. A panel of 24 judges active in the offshore oil and gas industry provided data for both the weighting and rating of six performance shaping factors. These data were subsequently processed by means of SLIM to calculate the probability of success for 18 muster actions ranging from point of muster initiator to the final actions in the temporary safe refuge (TSR). The six performance shaping factors considered in this work were stress, complexity, training, experience, event factors and atmospheric factors.     

Usage of human reliability quantification methods.

Human reliability quantification (HRQ) methods are becoming increasingly important in risk and accident assessment in systems these terms are usually related to (hi-tech industrial systems, including nuclear and chemical plants). These methods began to intensively develop after numerous accidents caused by human error or inadequate activity of people who controlled and managed complex technological processes. For already existing systems, but also for new ones, it is important to assess the possibility of an accident. Determination of possible preventive activities, which include the influence of human error on the safety of a system, is also required. These are the main goals of the HRQ method. Using Absolute Probability Judgment (APJ) and Success Likelihood Index Methods (SLIM) HRQ techniques in control and management centers in electro-power systems in Belgrade and railway traffic in Nis (both in Serbia and Montenegro) are shown in this paper.     

Fuzzy logic-based approach for identifying the risk importance of human error

In the system reliability and safety assessment, the focuses are not only the risks caused by hardware or software, but also the risks caused by “human error”. There are uncertainties in the traditional human error risk assessment (e.g. HECA) due to the uncertainties and imprecisions in Human Error Probability (HEP), Error-Effect Probability (EEP) and Error Consequence Severity (ECS). While fuzzy logic can deal with uncertainty and imprecision. It is an efficient tool for solving problems where knowledge uncertainty may occur. The purpose of this paper is to develop a new Fuzzy Human Error Risk Assessment Methodology (FHERAM) for determining Human Error Risk Importance (HERI) as a function of HEP, EEP and ECS. The modeling technique is based on the concept of fuzzy logic, which offers a convenient way of representing the relationships between the inputs (i.e. HEP, EEP, and ECS) and outputs (i.e. HERI) of a risk assessment system in the form of IF–THEN rules. It is implemented on fuzzy logic toolbox of MATLAB using Mamdani techniques. A case example is presented to demonstrate the proposed approach. Results show that the method is more realistic than the traditional ones, and it is practicable and valuable.     

航空维修差错模式及差错成因的灰色关联分析

提出一种基于HFACS-ME框架和灰色关联分析法的航空维修差错模式和差错成因之间关系的分析方法。利用该方法分别从"模式—成因"和"成因—模式"2个方向,以"技能差错"和"身体状态差"为例,对差错模式和差错成因之间的关系进行分析,得到影响"技能差错"的主要差错成因依次为空间狭窄、培训不足、工具损坏、身体状态差、精神状态差、空间阻碍,以及"身体状态差"主要影响的差错模式为记忆差错、决策差错、技能差错。结果表明,灰色关联分析法对航空维修差错模式和差错成因之间关系的分析是有效的、可行的。     

基于人因失误率预测法改进的事故后人因可靠性分析技术

人因可靠性分析是概率风险分析的重要组成部分,事故后人因事件分析是人因可靠性分析的核心内容.工程应用中的人因可靠性分析技术应在满足分析准确性需求的基础上尽可能简单与规范.本文分析了人因失误率预测法(THERP)的主要不足及事故序列评估程序人因可靠性分析技术(ASEP HRA)所做出的重要改进,描述了事故后ASEP HRA在工程应用中的基本程序,给出了一个应用实例.     

Risk assessment tools incorporating human error probabilities in the Japanese small-sized establishment

Although it has been estimated that as many as 80% of all occupational accidents have human errors as a cause, no risk assessment tools incorporating human-related elements have been developed for small companies. Human error probability (HEP) and human error analysis (HEA) have been used for large-scale, safety-critical industries for last three decades, but these tools are not suitable for smaller, more general industries that comprise the majority of accident settings.Here, we describe and verify a risk assessment tool that includes human-related elements for small companies. The tool expands on traditional risk assessment methods, such as matrix, risk graph and numerical scoring method, by adding human-related elements. The tool is easy-to-use in occupational environments, and includes assessments of human behavior and potentially outdated machinery at work place.     

A guide for assessing control room operator performance using speed and accuracy,perceived workload,situation awareness,and eye tracking

In the petrochemical industry, control room operators must address safety-critical alarms and other tasks using complex interfaces. This study developed a guide for assessing human performance using standard human factors measurement tools, and tested the sensitivity of those tools with two interface designs (i.e., gray and black) at three levels of workload (i.e., easy, medium, and difficult). The guide measures human performance through speed and accuracy, perceived workload using two standard instruments (i.e., NASA Task Load Index (NASA-TLX) and Subjective Workload Assessment Technique (SWAT)), situation awareness through the Situation Awareness Global Assessment Technique (SAGAT), and gaze through eye tracking coordinates. Twelve engineering student participants completed one simulation session at each of the three workload levels using one of two interface designs. Workload was manipulated through the number of simulated events (failures) in each session. Overall, the speed and accuracy measures, workload ratings, and eye tracking showed sensitivity to differences in workload level, and situation awareness showed sensitivity to the interaction between workload level and interface type. None of the tools were sensitive to interface type alone. Accuracy was highest under easy workload. Time per failure decreased at higher workload levels. Perceived workload ratings from the SWAT increased as workload increased, but workload ratings from the NASA-TLX were not different across workload levels. When workload increased, situation awareness remained steady for the gray interface but decreased sharply for the black interface, illustrating an interaction effect. Finally, the percentage of time spent looking at different areas of the screen during steady-state periods differed among workload levels. The tools in this guide can be used in the petrochemical industry to make design decisions for control room interfaces when workload levels are a concern.     

基于直觉三角模糊TOPSIS的高铁列车调度指挥人因失误风险排序

针对高速铁路调度指挥人因风险排序问题,从人因失误概率、人因失误探测度、人因失误重要度和事故严酷度四个方面构建风险评价指标体系。考虑到人因风险指标的模糊性和不确定性,用直觉三角模糊数描述各指标值,基于直觉模糊熵计算指标客观权重,然后建立基于TOPSIS法的高铁列车调度指挥人因失误风险排序模型。最后,基于实例验证了排序模型的实用性。     

人因可靠性数据库基础架构研究

针对人因可靠性分析中的数据匮乏问题,在技能-规则-知识(SRK)模型的基础上建立层次化的人因可靠性数据分类体系,其中包括人因失误模式和人因失误影响因素。结合对一些实际人因失误数据的考察,以及可控实验,确定人因可靠性数据库中基准人因失误概率。在人因数据外推系统中,使用层次分析法(AHP)来定量评价人因失误所处的情境的等级,并使用概率方法将基准人因失误概率与情境进行叠加,从而得到人因失误概率。人因数据库有助于人因可靠性数据的搜集和分析,形式化的外推方法减少了对主观因素的依赖。     

CREAM方法中控制模式分类的模糊方法

认知可靠性与差错分析方法(CREAM)通过对任务环境进行分析从而直接确定人为差错发生概率。该方法提出控制模式的概念,认定不同的任务环境下可能对应不同的控制模式,而人为差错概率直接由控制模式确定。因此,确定控制模式是其中的关键环节。针对该问题,笔者提出了一种模糊方法。通过对性能影响因子进行打分对任务环境进行量化,利用专家打分的方式确定性能影响因子分值对于控制模式的隶属度;通过拟合分析确定性能影响因子的分值对控制模式的隶属函数,得到控制模式与分值之间的对应关系;将该方法应用到两个示例中,其结果与原有方法的结果基本一致。     

基于熵权-HDT的航空器维修人误概率确定

人误是造成民用航空维修差错的主要因素。为确定不同情境下人误发生概率,结合某维修基地具体情况,采用熵权法确定主要的影响因子,并基于全决策树法分析主要影响因子对航空器维修人误概率的影响程度。计算结果显示,该维修基地人因可靠性的主要影响因子包括航空器维修人员的安全态度、技能、沟通、工作环境、压力以及工段长领导能力。根据各主要影响因子的不同品质描述等级组合,确定该情境下航空器维修人员的人误概率。鉴于该维修基地人因可靠性影响最明显的因子是"沟通",提出信息及时交流、明确沟通重要性等解决措施。     

Perceived Discomfort and Electromyographic Activity of the Upper Trapezius While Working at a VDT Station

Ten female participants performed work at a video display terminal (VDT) station over a whole working day. Subjective local muscular fatigue was evaluated by means of the Category Ratio 10 scale. Electromyographic activity of the upper right and left trapezius was measured. A comparison was made between 5 participants who had previous complaints and 5 participants who reported no musculoskeletal problems in the shoulder-neck region. The subjective scores for the shoulder differed significantly between the two groups, being higher for the group with complaints. Both groups showed a decrease in discomfort after the lunch break. The activity of the trapezius increased significantly for both groups, in a more pronounced way for the group with disorders. Although it is found in literature that VDT work is a task with very low static loads, it seems from this study that the EMG activity increase can be an indication of muscle fatigue: More effort was required to accomplish the same VDT task at the end of the day.     

The impact of job security,satisfaction and stress on performance assessment and optimization of generation companies

In this study, performances of Iranian thermal power plants have been assessed with respect to human factors such as job stress, satisfaction and security through data envelopment analysis (DEA). In the first step performance of power plants (DMUs) have been evaluated considering traditional production factors including installed capacity, internal consumption and fuel consumption as inputs and gross production as output (model 1). In the next step, model 1 is expanded to include three above mentioned human factors (model 2). Power plants have been ranked based on their relative efficiency scores in both models. Pearson and Spearman correlation coefficients between relative efficiency scores and rankings of power plants in two models have been calculated. The results show that efficiency scores and rankings of power plants in two models are quite different indicating that mentioned human factors have direct impact on overall performance of generation companies and that if we were to use just traditional factors it would not reflect the optimum efficiency of the DMUs. Finally, job security has been found as the most effective human factor in Iranian power plants. This is the first study that presents an integrated approach for assessment of electric power plants considering job stress, security and satisfaction. And it is shown that these human factors play important role in overall performance of generation companies.     

Comparing the usability and reliability of a generic and a domain-specific medical error taxonomy

Medical error taxonomies are used to report and analyse patient safety incidents. Medical error taxonomies can be generic or domain-specific. In comparing generic and domain-specific medical error taxonomies, the literature compares the information both type of taxonomies classify. There is little evidence the taxonomies have been compared in terms of usability and reliability. Twenty nurses and 21 pharmacists participated in a study comparing the usability and reliability of a generic medical error taxonomy and a medication error taxonomy. The medical error taxonomies utilized were the Patient Safety Event Taxonomy and the NCC MERP Taxonomy of Medication Error. The study found no significant difference in the usability ratings of both taxonomies. The taxonomies required different amount of time to classify patient safety incidents and had significantly different reliability levels. The reliability of the NCC MERP Taxonomy of Medication Error was significantly different when used by nurses and pharmacists. The taxonomy was also preferred by the majority of participants. Some recommendations are made about the design of future medical error taxonomies.