冗余系统应用于安全管理的探讨

利用故障树方法证明了系统中增加有效的冗余件能大大增加系统的安全性，提高设备的本质安全化的水平，加强了安全管理的效果，同时对冗余系统的插入方式进行了分类，列举了应用实例。     

Risk analysis for oil & gas pipelines: A sustainability assessment approach using fuzzy based bow-tie analysis

Vast amounts of oil & gas (O&G) are consumed around the world everyday that are mainly transported and distributed through pipelines. Only in Canada, the total length of O&G pipelines is approximately 100,000 km, which is the third largest in the world. Integrity of these pipelines is of primary interest to O&G companies, consultants, governmental agencies, consumers and other stakeholder due to adverse consequences and heavy financial losses in case of system failure. Fault tree analysis (FTA) and event tree analysis (ETA) are two graphical techniques used to perform risk analysis, where FTA represents causes (likelihood) and ETA represents consequences of a failure event. ‘Bow-tie’ is an approach that integrates a fault tree (on the left side) and an event tree (on the right side) to represent causes, threat (hazards) and consequences in a common platform. Traditional ‘bow-tie’ approach is not able to characterize model uncertainty that arises due to assumption of independence among different risk events. In this paper, in order to deal with vagueness of the data, the fuzzy logic is employed to derive fuzzy probabilities (likelihood) of basic events in fault tree and to estimate fuzzy probabilities (likelihood) of output event consequences. The study also explores how interdependencies among various factors might influence analysis results and introduces fuzzy utility value (FUV) to perform risk assessment for natural gas pipelines using triple bottom line (TBL) sustainability criteria, namely, social, environmental and economical consequences. The present study aims to help owners of transmission and distribution pipeline companies in risk management and decision-making to consider multi-dimensional consequences that may arise from pipeline failures. 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. A simple example is used to demonstrate the proposed approach.     

ACT method for safety training: An approach to improve on-site safety performance

Unsafe behavior is one of the main causes limiting the improvement of on-site safety performance. Safety training is an important means of preventing unsafe behavior. With changes in the scale of operations and employee characteristics, traditional training methods have largely failed to meet the practical demands. Therefore, to improve the effectiveness of safety training, this paper analyzes the shortcomings of the current training methods, demonstrates the potential value of accident cases for improving the training effect, and the advantages of 24Model for case analysis in safety training. Subsequently, this paper constructs a systematic training system with Accident-Cause-Training (ACT) as the training relationship chain, which runs the accident cases throughout the training process, 24Model is utilized to trace the unsafe behaviors that lead to accidents from the perspectives of organizational and individual level, and the training content is established according to the analysis results. This paper also conducts a case study to verify the operability of the ACT method, specifically, a training programme for limited space operations at a national-level oil and gas storage and transportation company is designed and implemented. Finally, by comparing the similarities and differences between the ACT method and other training methods from various perspectives, the universality and participation of the ACT method are proved, and the development trend of the ACT method is also discussed. It is believed that the proposed ACT method could enrich the types of safety training methods and provide an effective and scientific tool to enhance the safety performance of field operations.     

Improving safety and availability of complex systems using a risk-based failure assessment approach

This paper presents a structured risk-based failure assessment (RBFA) approach, which provides a complete solution to avoid repeated and potential failures to improve overall plant safety and availability. Technological advancements and high product demand have encouraged designers to design mega-capacity systems to enhance system utilization and improve revenues. However, these benefits make the systems more complex and thus prone to unnoticed failure. It is an overwhelming task to address all the failures due to the limited resources and time constraints. This leads to substandard and poor quality failure assessments, which cause repeated failures. To address this common industry concern, a four phase RBFA framework is proposed which is not limited to the identification of root cause(s) but also includes other actions such as failure monitoring. The four phases include the plan phase, the assessment phase, the analysis phase and the implementation-tracking phase. These phases cover identification of failure, failure analysis, root cause(s) analysis, and failure monitoring. In this paper, the applicability and advantages of the proposed approach are examined through two real case studies pertaining to bearing failure and drive coupling failure. By implementing the proposed approach, significant improvements have been experienced in the system availability in both the cases.     

A new approach for facility siting using mapping risks on a plant grid area and optimization

The present work is focused on developing a methodology to find the optimal placement of a hazardous process unit and other facilities using optimization theory while considering a risk map in the plant area. Incidents can have possible consequences resulting from flammable gas releases, which can be evaluated by using consequence modeling programs. The probability of each incident can be derived from initial leak hole size estimation through event tree analysis. In this methodology the plant area was divided into square grids and risk scores were estimated for each grid. The overall cost is a function of the probable cost of property damage due to fires or explosions and the interconnection cost including piping, cable, and management. The proposed approach uses a mixed integer linear optimization programming (MILP) that identifies attractive locations by minimizing the overall cost. A case study is presented for a hexane–heptane separation facility that considers the meteorological data for the given area in order to show the applicability of the proposed methodology. Results from this study will be useful in assisting the selection of locations for facilities and for risk management.     

Towards a European energy risks monitor to consistently map safety and security risks of different energy infrastructures

After mapping of current European Union regulations on the management of accident risks related to natural hazards and different industrial activities, this paper discusses insights from past and current European Commission initiatives on harmonisation of assessment and management of safety risks. The problem of safety comparison and risk/benefit communication is of critical importance for sustainable decision making. For the specific case of the energy sector, the European Commission’s Joint Research Centre (DG JRC) and DG TREN (Directorate General for Transport and Energy) have recently started two connected initiatives, called energy risks monitor (ERMON) and safety and security of energy infrastructures in a comparative view (SEIF-CV). While ERMON deals with the development of a methodology and corresponding web-based information system to cross-compare in a consistent way safety, risk and reliability performances of different energy systems (fossil, nuclear, renewables) across their specific fuel cycle chains, SEIF-CV creates a corresponding network of stakeholders in the energy sector as well as the necessary review and user panels for ERMON. Objectives and status of ERMON and SEIF-CV are described.     

An innovative and comprehensive approach for the consequence analysis of liquid hydrogen vessel explosions

Hydrogen is one of the most suitable solutions to replace hydrocarbons in the future. Hydrogen consumption is expected to grow in the next years. Hydrogen liquefaction is one of the processes that allows for increase of hydrogen density and it is suggested when a large amount of substance must be stored or transported. Despite being a clean fuel, its chemical and physical properties often arise concerns about the safety of the hydrogen technologies. A potentially critical scenario for the liquid hydrogen (LH₂) tanks is the catastrophic rupture causing a consequent boiling liquid expanding vapour explosion (BLEVE), with consequent overpressure, fragments projection and eventually a fireball. In this work, all the BLEVE consequence typologies are evaluated through theoretical and analytical models. These models are validated with the experimental results provided by the BMW care manufacturer safety tests conducted during the 1990's. After the validation, the most suitable methods are selected to perform a blind prediction study of the forthcoming LH₂ BLEVE experiments of the Safe Hydrogen fuel handling and Use for Efficient Implementation (SH₂IFT) project. The models drawbacks together with the uncertainties and the knowledge gap in LH₂ physical explosions are highlighted. Finally, future works on the modelling activity of the LH₂ BLEVE are suggested.     

Occupational and public health and safety in a changing work environment: An integrated approach for risk assessment and prevention

During recent years the work environment has undergone significant changes regarding working time, years of employment, work organization, type of employment contracts and working conditions. In this paper, consequences of these changes on occupational and public health and safety are examined. These include the disruption of human biological rhythms, the increase of workers fatigue due to changes in patterns of working hours and years of employment, job insecurity and occupational stress, which have a serious impact on workers’ health and may result in an increase in occupational accidents. Unsafe work practices related to workload and time pressure, the impact of work changes on public safety and the deterioration of workers’ living conditions with respect to income, social-family life, health and insurance benefits, are also described. In this context, difficulties that occur due to the changing work environment in conducting effective occupational risk assessments and implementing OSH measures are discussed (for example, frequent changes between tasks and workplaces, underreporting of occupational accidents and diseases, lack of methodological tools, etc.). A fundamental criterion used while studying consequences on health and safety and the relative preventive measures is that health and safety must be approached as ‘the promotion and maintenance at the highest degree of the physical, mental and social well-being of workers’ and not only as retention of their work ability. Limits in combining “flexibility” at work and overall protection of occupational and public safety and health in a competitive market are put forward for discussion.     

An evaluation approach using a HARA and FMEDA for the hardware SIL

Safety instrumented systems (SIS) are becoming increasingly complex, and form a growing proportion of programmable electronic parts. The IEC 61508 global standard was established to ensure the functional safety of SIS; however, it was expressed in highly macroscopic terms. The safety integrity level (SIL) is a criterion describing whether a component meets the safety requirements of a SIS. The safety requirements give a target SIL for the expected risks using hazard analysis and risk assessment (HARA). The SIL must correspond to the safety requirements. This study introduces an evaluation process for determining the hardware SIL through failure modes, effects, and diagnostic analysis (FMEDA). First, the components of the SIS subsystem are defined in terms of failure modes and effects, and then the failure rate and failure mechanism distribution are assigned to each component. The safety mode and detectability of each failure mode are determined for each component and, finally, the hardware SIL is evaluated. We perform a case study to evaluate the hardware SIL of the flame scanner system using HARA and FMEDA, where the safety requirement of the flame scanner was determined using the risk graph method. We verified that the hardware SIL of the flame scanner corresponded to the safety requirement.     

Organisational safety indicators: Some conceptual considerations and a supplementary qualitative approach

This article discusses the extent to which indicators can represent organisational qualities in relation to safety and how a qualitative approach called the Operational Safety Condition (OSC) method can be a supplement and help improve safety. In light of the recent Safety Science debate on safety indicators, we suggest that it is difficult to capture organisational conditions using indicators, although they are indisputably important when identifying the risk of accidents. Safety climate and risk analysis approaches are discussed as methods that can build and assess indicators in relation to organisational safety quality. OSC and similar qualitative approaches can capture the complexity of organisational conditions, aid organisational learning at a double loop level and offer a tool for risk management.     

基于过程方法的职业健康安全管理体系探讨

职业健康安全管理体系在煤炭行业获得了广泛认可和应用,对提高煤炭行业的职业健康安全管理水平起到了较大的促进作用.OSAS18001、ISO9001与ISO14001等管理体系标准均推荐采用过程方法,但煤炭行业鲜有应用.为了更好地在煤炭行业职业健康安全管理体系中贯彻过程管理模式,本文从TS煤矿职业健康安全管理体系的建立与运行、过程分析以及审核方法等方面入手,结合TS煤矿的实际,介绍了过程方法在煤矿职业健康安全管理体系中的应用.     

A novel Dempster-Shafer theory-based approach with weighted average for failure mode and effects analysis under uncertainty

Risk priority number (RPN) is a commonly-used prioritization method in failure mode and effects analysis (FMEA) for systemic reliability and safety study. However, conventional RPN confronts wide criticisms, due to the neglect of the uncertainties of experts' opinions. It is important to handle the conflicts among experts' multi-opinions which could be described in imprecise, incomplete or crisp forms in lack of knowledge. In this paper, a novel method is proposed to alleviate and/or eliminate counter-intuitive behaviors against conflicts among multi-opinions under Dempster-Shafer theory. Firstly, the abnormity test for experts’ opinions is undertaken to identify and discard those distinct judgments. Then, an approach to determining the subjective weights of experts is proposed, which is used in weighted average for multi-opinions before calculating RPNs. Finally, the risk priority evaluation on main engine crankcase explosion failure on-board ship is implemented to verify the feasibility of the proposed approach.     

安技人员素质与工伤事故关系问题的探讨

以中国飞行试验研究院安全技术人员配置状况为研究对象 ,结合近 2 0年来工伤事故情况 ,从安技人员文化基础、专业知识、工作年龄、安全年限等方面 ,研究分析安技人员素质与工伤事故的关系及其规律。目的是为安技人员的素质建设以及充分发挥安技人员积极性提供有效的依据和帮助     

Logistic regression model for prediction of roof fall risks in bord and pillar workings in coal mines: An approach

The roof fall hazards are the major problems in underground coal mines, which are generally unpredictable due to the associated uncertainties arising out of the complexity of geological conditions and variability in mining parameters. During the six year period, 1996–2001, 253 Indian coal miners lost their lives and 401 are seriously injured in 490 different roof fall accidents. In India, 32.7% of the total fatal injuries in coal sectors are due to roof fall in bord and pillar method of workings. This paper attempts to predict the severities of roof fall accidents based on some major contributing parameters using the binary logistic regression model. In total, 128 roof fall accidents for the last few years from five underground coal mines in India having bord and pillar method of working are analyzed for this study. The results revealed that wider gallery width is more prone to major and serious accidents than narrower gallery width. Thin seams are more amenable to major accidents in comparison to thick seams. Unsupported or partially supported roofs have higher risk for contributing major as well as serious accidents. Deep workings are more prone to major accidents as compared to shallow depth workings.     

Managing the condition-based maintenance of a combined-cycle power plant: An approach using soft computing techniques

This paper describes how a condition-based maintenance plan was developed for a combined-cycle power plant at a medium-sized Italian refinery. Including forecasting activities in the maintenance cycle achieved the dual goal of identifying any need for measures ahead of the deadlines established for routine preventive maintenance in the event of alarm conditions being detected, and of postponing any scheduled measures in the event of the components in question still being in good condition. Soft computing tools were experimentally used to achieve these objectives. Recurrent neural nets and neuro-fuzzy systems were used to ensure that the assessment of the trends of the global values was effective in determining the time remaining before the next outage period was needed. Using these tools enabled an accurate prediction of the values of the vibrations on rotating machinery based on the values of the operating parameters given as input.The plan was part of a maintenance management scheme seen as a container of inspection activities providing the foundations for systematically organizing certain servicing measures (e.g. the replacement of bearings, or alignments on rotating machinery, etc.), and to prevent sudden breakdown situations.     

Team effectiveness under stress: a structural contingency approach

To examine whether working under stressful circumstances restricts or enhances team effectiveness, a structural contingency model for team effectiveness was tested by focusing on job structuring (mechanistic/organic structuring) as a key factor, which interacts with qualitative and quantitative stress on team attitude (team commitment) and outcomes (team effectiveness). Findings from 73 primary care teams indicated that mechanistic structuring for teams working under quantitative stress was positively associated with team commitment, which in turn fostered team effectiveness, whereas organic structuring for working under qualitative stress improved team effectiveness. Furthermore, team commitment mediated the relationships between stress and structuring and team effectiveness. These findings support a structural contingency model for improving team effectiveness under stress. Copyright © 2006 John Wiley & Sons, Ltd.     

A pattern of contractor selection for oil and gas industries in a safety approach using ANP-DEMATEL in a Grey environment

Contractor selection is one of the major concerns of industry managers such as those in the oil industry. The objective of this study was to determine a contractor selection pattern for oil and gas industries in a safety approach. Assessment of contractors based on specific criteria and ultimately selecting an eligible contractor preserves the organizational resources. Due to the safety risks involved in the oil industry, one of the major criteria of contractor selection considered by managers today is safety. The results indicated that the most important safety criterion of contractor selection was safety records and safety investments. This represented the industry’s risks and the impact of safety training and investment on the performance of other sectors and the overall organization. The output of this model could be useful in the safety risk assessment process in the oil industry and other industries.     

POLSSS: surveying stakeholders about acceptability of risks and system changes

This paper describes two surveys that were carried out during the Policy for Sea Shipping Safety (POLSSS) project [Walker, 2000. POLSS: overview and cost-effectiveness analysis. Safety Science 35 (1–3, 105–121]. The first focused on the acceptability of risks. Its main goal was to find out how stakeholder groups accept different risks involved in maritime transport. The respondents were asked about their acceptance of the current risks and situations where the risks are either increased or decreased. The second survey examined the non-risk-related acceptability of different policy measures — both those being used currently, and those being considered in the POLSSS project for future implementation.