Lagging or leading? Exploring the temporal relationship among lagging indicators in mining establishments 2006–2017

Problem: Safety management literature generally categorizes key performance indicators (KPIs) as either leading or lagging. Traditional lagging indicators are measures related to negative safety incidents, such as injuries, while leading indicators are used to predict (and therefore can be used to prevent) the likelihood of future negative safety incidents. Recent theory suggests that traditional lagging indicators also possess characteristics of leading indicators, and vice versa, however empirical evidence is limited. Method: The current research investigated the temporal relationships among establishment-level injuries, near misses, and fatal events using injury and employment data from a sample of 24,910 mining establishments over a 12-year period. Results: While controlling for employee hours worked, establishment-level reported injuries and near misses were associated with of future fatal events across the sample of mines and over the time period studied. Fatal events were also associated with increases in future reported near misses, providing evidence of a cyclic relationship between them. Discussion: These findings challenge the strict categorization of injuries, near misses, and fatal events as lagging indicators. Practical applications: Understanding the KPIs that should be used to manage organizational safety, and how they can be used, is of critical practical importance. The results of the current study suggest that, depending on several considerations, metrics tied to negative safety incidents may be used to anticipate, and possibly prevent, future negative safety events.     

铁路车站计算机联锁控制系统的可靠性和安全性分析

铁路车站计算机联锁控制系统,直接关系到列车运行的安全.通过可靠性框图分析法,对采用不同冗余结构的铁路车站计算机联锁控制系统的可靠性和安全性的指标进行了分析和比较,并通过仿真计算对分析和比较的结果进行了验证,为铁路车站计算机联锁控制系统的选型提供了技术支持.     

Safety climate and hydrocarbon leaks: An empirical contribution to the leading-lagging indicator discussion

Hydrocarbon (HC) leaks are important initiating events for major accidents in the oil and gas industry. This study explores the extent to which a safety climate indicator from a survey on working conditions undertaken in an oil and gas company (n = 2188) can be used as a leading and/or lagging indicator in relation to HC leaks on 28 offshore installations. It was found that more negative safety climate scores were associated with increasing numbers of HC leaks over a 12-month period following the survey. The safety climate indicator explained more of the variance in HC leaks than technical indicators. HC leaks in the 12-month period preceding the survey did also correlate significantly with the safety climate indicator. More HC leaks during this period were associated with worse scores on the safety climate indicator. Thus, the results support that the safety climate measure could serve as leading and lagging indicator for HC leaks. The results and their possible implications are discussed.     

系统安全性与可靠性分析的故障树方法

探讨了大型复杂系统安全性与可靠性分析的故障树技术。阐述了国外具有代表性的几种建树方法。针对实际应用情况,提出了将建树过程划分为5个阶段,应遵循的8条基本准則。导出了典型系统可靠度与故障率等可靠性参数计算的通用公式。论述了故障树分析方法的特点及发展动向。     

The successes and challenges of implementing high reliability principles: A case study of a UK oil refinery

Research conducted on organisations that are able to sustain excellent safety records over long time periods suggests that there are a number of practices that organisations can adopt to achieve high levels of reliability and safety. These practices are often discussed in the context of major incidents to highlight the safety standards that high hazard organisations should try to emulate. However, previous research has predominantly focused on non-profit organisations, and comparatively little research has examined whether high reliability practices may be meaningfully applied to commercial contexts. This paper addresses this gap by using a qualitative approach to explore the types of reliability-enhancing practices implemented in a UK-based oil refinery in its attempt to achieve its ethos of ‘safe and reliable operations’. The findings illustrate the successful application of reliability-enhancing practices in several domains, including: hazard identification and control; emergency preparedness and collection; and analysis of incidents and near misses. Management commitment to safety emerged as an important factor underpinning the successful implementation of reliability-enhancing practices, highlighting its potential significance in the context of commercial organisations. However, promoting an open reporting culture and maintaining high levels of management visibility may be some of the challenges encountered by organisations striving to implement reliability-enhancing practices.     

火工品可靠性(或安全性)评估的Bayes方法

对火工品可靠性（或安全性）评估中通常采用的经典方法进行了剖析。介绍了数理统计方法学中近年来兴起的Ｂａｙｅｓ统计推断方法，并给出了此法在火工品二项分布、正态分布情况下，对可靠度评估的应用实例。     

[Case Study] CityCenter and Cosmopolitan Construction Projects, Las Vegas, Nevada: Lessons learned from the use of multiple sources and mixed methods in a safety needs assessment

Problem

The present study describes a response to eight tragic deaths over an eighteen month times span on a fast track construction project on the largest commercial development project in U.S. history.

Methods

Four versions of a survey were distributed to workers, foremen, superintendents, and senior management. In addition to standard Likert-scale safety climate scale items, an open-ended item was included at the end of the survey.

Results

Safety climate perceptions differed by job level. Specifically, management perceived a more positive safety climate as compared to workers. Content analysis of the open-ended item was used to identify important safety and health concerns which might have been overlooked with the qualitative portion of the survey.

Discussion

The surveys were conducted to understand workforce issues of concern with the aim of improving site safety conditions. Such efforts can require minimal investment of resources and time and result in critical feedback for developing interventions affecting organizational structure, management processes, and communication.

Summary

The most important lesson learned was that gauging differences in perception about site safety can provide critical feedback at all levels of a construction organization.

Impact on the Industry

Implementation of multi-level organizational perception surveys can identify major safety issues of concern. Feedback, if acted upon, can potentially result in fewer injuries and fatal events.     

基于模糊颜色Petri网的表决DVP安全软件模型初探

把模糊计算理论和有色Petri网有机地结合起来,提出了一种模糊颜色Petri网诊断表决算法,把该算法应用于DVP的软件模型,使之具有故障容忍和表决的能力.笔者对以模糊颜色Petri网为核心的DVP软件模型表决算法进行了较为深入的探讨,该模型对提高软件系统的安全性和可靠性具有实际意义.     

炸药及火工品可靠性与安全性评定方法

可靠性的评定结果是否可信,直接关系到炸药及火工品的使用安全性和作用可靠性.但是,现有炸药及火工品可靠性评定方法却存在着达不到置信度要求、评价结果偏于危险的缺点.为此,提出了一种确定炸药及火工品安全度和可靠度的高精度方法,并给出了应用实例.该方法不仅可信程度高,而且适用于小样本情况,尤其是在利用了以往试验数据后,既可提高安全性和可靠性评定的精度,又可大大节省试验的费用及时间.     

空气储罐安全临界裂纹的可靠性分析

通用失效评定图在评定焊接结构安全性方面广为采用.但是,材料力学性能的测试、结构中缺陷大小的测试,客观上存在一定不确定性.因此,不论是对评定参数还是评定结果都需要进行可靠性分析.但可靠性分析需要大量数据,有时难于实现.为此,在对随机变量的实验结果进行统计分析中,采用二维单侧容限方法,从而在不增加工作量的同时,确保了分析结果的高可靠性.在空气储罐安全临界裂纹分析计算中,经这一方法处理后,采用成功-失败法对指定失效概率进行求解,裂纹尺寸变动1 mm,其安全评定的失效概率则变动几个数量级.从而在充分挖掘储罐潜能的同时,大大提高了安全临界裂纹分析的可靠度.     

Reliability assessment of safety instrumented systems subject to different demand modes

Safety instrumented systems (SISs) are commonly used in the process industry, to respond to hazardous events. In line with the important standard IEC 61508, SISs are generally classified into two types: low-demand systems and high-demand systems. This article explores this classification by studying the SIS reliability for varying demand rates, demand durations, and test intervals. The approach is based on Markov models and is exemplified by two simple system configurations. The SIS reliability is quantified by the probability of failure on demand (PFD) and the frequency of entering a hazardous state that will lead to an accident if the situation is not controlled by additional barriers. The article concludes that very low-demand systems are similar and may be treated as a group. The same applies to very high-demand system. Between these group, there is a rather long interval where the demand rate is neither high-demand nor low-demand. These medium-demand systems need a specific treatment. The article shows that the frequency of entering into a hazardous state increases with the demand rate for low-demand systems, while it is nearly independent of both the demand rate and the demand duration for high-demand systems. The PFD is an adequate measure for the SIS reliability for low-demand systems, but may be confusing and difficult to interpret for high-demand systems.