Safety management systems and safety culture in aircraft maintenance organisations

A self-regulatory model was proposed to examine how different organisations manage safety, with particular emphasis on the human and organisational aspects. The relationships of different aspects of safety culture and safety management systems were explored through the deployment of different research measures and methods. Studies of four aircraft maintenance organisations included analysis of documentation and qualitative interviews, surveys of safety climate and attitudes, expected response to incidents and compliance with task procedures. The model was effective in analysing the salient features of each organisation' s safety management system, though it underestimated the roles of planning and change. The data from management interviews, the incidents survey and safety climate survey exhibited a large measure of agreement in differentiating between the different safety management systems and safety climate of the four organisations. The measures of compliance with task procedures and safety attitudes did not differentiate between the four organisations (though one organisation did differ from the others in safety attitudes). This suggests a strong, relatively homogeneous professional sub-culture of aircraft technicians spanning the different organisations. Differences in safety attitudes and climate were found between occupational groups, though in the case of climate the differences between occupational groups were a function of the organisation, suggesting a differentiated notion of safety culture. The professional sub-culture of technicians is likely to mediate between the organisation' s safety management system and safety outcomes.     

Ripples in a pond: an open system model of the evolution of safety culture.

The development of an effective safety culture is essential to promote safe operations. Previous studies have either identified the characteristics of effective safety culture analytically, inferring them from signs and symbols derived from working practices, or have restricted the study of the development of safety culture to workers within an organisation. This paper describes a large-scale survey-based study in which the factors influencing the evolution of safety culture are identified empirically and, drawing upon open systems theory, are also extended beyond the bounds of the organisation. Three major determinants of safety culture are identified: safety concerns, influences and actions. Sub-components within each of these categories are also identified and the relationship between them is hypothesised.     

Assessing the maintenance unit of a nuclear power plant – identifying the cultural conceptions concerning the maintenance work and the maintenance organization

Various organizational accidents have indicated that the shared interpretations and experiences of the personnel concerning the work, the organization, and the associated risks are of crucial importance for the safety and effectiveness of the operations. These conceptions are an element of the organizational culture. The cultural conceptions should thus be studied and their contribution to the organizational safety and effectiveness should be assessed proactively. Nevertheless, organizational assessments often focus on either the general safety attitudes and/or values of the personnel, or formal organizational structures and the official practices. In this article a case study is reported that was carried out in a Nordic nuclear power plant maintenance unit. We will illustrate how the employees in the organization construct their work, their organization and the demands of the maintenance task. We focus on explicating and assessing the cultural conceptions prevalent in the maintenance organization. Our aim is to illustrate how the cultural conceptions and organizational practices, tools and the organizing of the work and the organizational climate influence each other, and how they relate to the demands of the maintenance work. The principal methods utilized in the case study were organizational culture questionnaire (CULTURE), semi-structured interviews, group working, and personnel development seminars.     

Exposure to fall hazards and safety climate in the aircraft maintenance industry

PROBLEM: Falls represent a significant occupational hazard, particularly in industries with dynamic work environments. This paper describes rates of noncompliance with fall hazard prevention requirements, perceived safety climate and worker knowledge and beliefs, and the association between fall exposure and safety climate measures in commercial aircraft maintenance activities. METHODS: Walkthrough observations were conducted on aircraft mechanics at two participating facilities (Sites A and B) to ascertain the degree of noncompliance. Mechanics at each site completed questionnaires concerning fall hazard knowledge, personal safety beliefs, and safety climate. Questionnaire results were summarized into safety climate and belief scores by workgroup and site. Noncompliance rates observed during walkthroughs were compared to the climate-belief scores, and were expected to be inversely associated. RESULTS: Important differences were seen in fall safety performance between the sites. The study provided a characterization of aircraft maintenance fall hazards, and also demonstrated the effectiveness of an objective hazard assessment methodology. Noncompliance varied by height, equipment used, location of work on the aircraft, shift, and by safety system. DISCUSSION: Although the expected relationship between safety climate and noncompliance was seen for site-average climate scores, workgroups with higher safety climate scores had greater observed noncompliance within Site A. Overall, use of engineered safety systems had a significant impact on working safely, while safety beliefs and climate also contributed, though inconsistently. IMPACT ON INDUSTRY: The results of this study indicate that safety systems are very important in reducing noncompliance with fall protection requirements in aircraft maintenance facilities. Site-level fall safety compliance was found to be related to safety climate, although an unexpected relationship between compliance and safety climate was seen at the workgroup level within site. Finally, observed fall safety compliance was found to differ from self-reported compliance.     

Measuring maintenance culture and maintenance core task with CULTURE-questionnaire––a case study in the power industry

Organisational culture has become a focus of much attention in industry in general and the nuclear industry in particular. In maintenance work, the research has addressed mainly human error issues or strategic decision making and optimisation. The present study utilises the CULTURE-questionnaire that is designed to measure the different cultural aspects of complex organisations. Functioning of the questionnaire and the results obtained in a case study at a maintenance organisation of a nuclear power plant are reported in this paper. The questionnaire consisted of four instruments: measures of values, psychological job characteristics, individual perceptions and organisational core task. Three of the instruments were factor analysed and 13 summated scales were formed. The core task instrument was used in a cluster analysis to separate the respondents into groups on the basis of their orientation towards the maintenance work. Differences between the work tasks, section, age and length of service were studied. Hierarchical position in the company influenced perceptions of values. Core task orientation influenced the perception and subjective feelings towards one's organisation. Several partially overlapping subcultures were thus identified. The implications of the different work orientations for effective maintenance are discussed.     

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。     

CESSNA172R飞机飞行操纵钢索故障原因分析

CESSNA172R飞机飞行操纵(副翼、升降舵、方向舵、襟翼)系统钢索多次发生磨损、断裂故障,严重威胁了飞行安全。根据该机型结构设计特点,通过相似机型系统类比、数据可靠性分析等方法分析了各飞行操纵系统钢索失效的主要原因,提出了预防飞行操纵钢索失效的措施。通过调整飞机的操纵钢索系统的维护周期,改进钢索的检查和维护技术,提高飞机在全寿命周期中的安全可靠性。     

基于SEM的维修资源管理对机务人员不安全行为的影响研究

为减少维修差错导致的不安全事件,从维修资源管理对机务人员不安全行为的影响进行探讨,以团队合作、沟通交流、工作压力、领导能力、工作环境及惯例作为维修资源管理变量,考虑不安全行为意向对不安全行为的中介作用,提出了维修资源管理各因素对机务人员不安全行为的影响假设。通过实证分析,采用结构方程模型(SEM)的方法验证了维修资源管理各因素对机务人员不安全行为的影响假设。实证结果表明:维修资源管理各因素对机务人员不安全行为及意向有不同的影响作用。为机务人员的安全行为管理提供理论支持。     

Values-in-action that support safe production

Introduction: Safe production is a sustainable approach to managing an organization’s operations that considers the interests of both management and workers as salient stakeholders in a productive and safe workplace. A supportive culture enacts values versus only espousing them. These values-in-action are beliefs shared by both management and workers that align what should happen in performing organizational routines to be safe and be productive with what actually is done. However, the operations and safety management literature provides little guidance on which values-in-action are most important to safe production and how they work together to create a supportive culture. Method: The researchers conducted exploratory case studies in 10 manufacturing plants of 9 firms. The researchers compared plant managers’ top-down perspectives on safety in the performance of work and workers’ bottom-up experiences of the safety climate and their rates of injury on the job. Each case study used data collected from interviewing multiple managers, the administration of a climate survey to workers and the examination of the plant’s injury rates over time as reported to its third party health and safety insurer. Results: The researchers found that plants with four values-in-action —a commitment to safety, discipline, prevention and participation—were capable of safe production, while plants without those values were neither safe nor productive. Where culture and climate aligned lower rates of injury were experienced. Discussion and conclusion: The four value-in-actions must all be present and work together in a self-reinforcing manner to engage workers and managers in achieving safe production. Practical application: Managers of both operations and safety functions do impact safety outcomes such as reducing injuries by creating a participatory environment that encourage learning that improves both safety and production routines.     

基于模糊贴近度和熵权的航空装备维修安全综合评价

航空装备维修安全是确保装备飞行安全的重要因素,为提高航空装备飞行的安全性,需要对航空装备维修安全进行准确评价。根据航空装备维修安全评价涉及的不确定性问题,采用模糊数学和熵理论,提出一种基于模糊贴近度和熵权的航空装备维修安全综合评价方法。在建立航空装备维修安全评价指标体系的基础上,采用熵确定各指标的权重值、加权平均算子确定综合评价集,利用非对称贴近度进行决策分析。通过对某型飞机调查数据的算例分析,确定航空装备维修安全的主要影响因素,得出该型飞机维修安全水平的评价值。     

企业安全生产主体责任绩效评估建模与应用

在全面分析企业安全生产主体责任内涵的基础上,采用问卷调查、访谈等多种手段,从企业依法生产经营、组织机构与人员配置、安全教育培训、员工权益维护、规章制度管理、作业场所管理及事故管理等方面建立系统的企业安全生产主体责任绩效评估指标体系;结合层次分析法和变权综合理论,构建企业安全生产主体责任绩效评估模型,并进行实例应用。结果表明:依法生产经营是对进行安全生产主体责任绩效评估的前提,机构与人员设置、作业场所安全、规章制度、安全教育培训、事故管理、员工权益维护等子体系对落实企业安全生产主体责任的重要性程度依次递减,所构建的企业安全生产主体责任绩效评估方法和模型是有效的。     

Safety culture in railway maintenance

This paper discusses the practical problems of understanding and addressing unsafe behaviour and negative safety culture in rail maintenance. A well grounded qualitative approach informed the research methodology. Analysis of interviews with staff enabled identification of forty main factors that influence safe behaviour and safe culture. These factors ranged in proximity of their connection to the unsafe event, from those that could be found at trackside and which directly influence the behaviour of the track workers on the day (e.g. weather), to more medium term and distanced factors (e.g. supervisors’ style of management), to those at considerable distance in terms of where they emanate and can be changed, such as contradictory rules. As a result of this deep, structured qualitative enquiry, the maintenance company most concerned has disseminated findings throughout the organisation and has set a strategy to improve both safety systems and behaviour.     

Effective environmental management through life cycle assessment

Unplanned and unsustainable development (particularly rapid industrialisation) has placed great pressure in every dimension of the environment (air, water, soil, health, etc.). The resulting disturbance in the natural ecological balance is a serious concern. Sustainable development is the need of the hour; it can only be achieved through effective environmental management. Environmental management will become indispensable in the future as regulatory restrictions tighten and public expectations of environmental performance increase. The day is not far away when a customer will prefer to buy products produced by an environmentally committed organisation. In short, the environmental commitment of an organisation will become a market strategy.

Environmental management is a set of actions based on a structured methodology to ensure that an organisation is committed to the environment and that the production process has minimal/no adverse affect on it. This article emphasises environmental management in the real engineering sense of the term, and discusses how to develop an effective environmental management system through life cycle assessment. It further demonstrates through a real life case study how an industry has achieved landmark success in managing its environment, production, as well as winning the good faith of society.     

Lessons learnt from a crisis event: How to foster a sound safety culture

Recent events in the nuclear industry have blamed a declining safety culture both on the utility and regulatory side as the major responsible. Confidence in the nuclear industry can be dramatically affected by such events. In this context, the present paper analyses a recent crisis event that involved a research reactor. It shows the time history of the event and how its escalation brought to a temporary shut down of the reactor. In-depth analysis of the event pointed out safety culture deficiencies within the organization. The paper presents the key elements in the ensuing organizational change process and describes the different phases (short and long term approaches), players and measures involved in the process that the organisation set up to address deficiencies and improve safety culture. The case represents an interesting example from which important lessons can be learnt. In particular, staff motivation in terms of involvement in improvement activities is considered central in managing safety.     

民机客舱安全疏散能力模糊综合评价

随着民航业高速发展,民航客机飞行事故和严重事故征候时有发生,并且很难完全避免,因此做好民机客舱安全疏散对减少人员伤亡损失有着重要意义。通过对影响民机客舱安全疏散的各种指标进行定性分析,建立民机客舱安全疏散能力评估指标集,应用层次分析法得到各指标的权重,建立多级模糊综合评价模型及安全评价等级模型。最后将此方法应用到实际案例中,得到某航空公司的客舱安全疏散能力评价结果,通过进一步分析并对该航空公司安全管理提出指导性建议。     

BP神经网络在航空机务人员本质安全程度评价中的应用

航空机务是飞机安全服役的重要保障,为提高航空机务系统的本质安全性,需要对航空机务人员的本质安全程度进行准确评价。在对本质安全人进行定义并明确航空机务人员本质安全程度评价项目后,构建了一种基于MATLAB的用于本质安全程度评价的BP神经网络模型。实例分析中,以某航空公司10位机务人员的专家打分数据作为样本输入,在对输入数据进行标准化处理,并明确期望输出后,通过编程计算,确定了网络隐含层神经元的最佳数目。采用优化结构进行仿真计算,结果表明BP网络的期望输出值和实际仿真输出值能较好吻合,证实了模型的可信性。基于BP网络的航空机务人员本质安全程度评价具有较好的适用性和可行性。     

Applying systems thinking concepts in the analysis of major incidents and safety culture

In recent years, investigations into major incidents often highlight poor safety culture as one of the key causal factors. These investigations are often assisted by causal analysis tools that help to ensure that the investigation and the information captured are systematic. However, current causal analysis tools are not designed to analyse dynamic complexity of major incidents and safety culture, which arises from the interactions between actors and the temporal and spatial gaps between actions and consequences. This is because most causal analysis tools model events and causal factors linearly. In contrast, systems thinking, a discipline of seeing systems holistically, emphasises the circular nature of complex systems, i.e. cause and effect are not distinguishable. This paper proposes that traditional causal analysis tools and investigation should be enhanced with the use of systems thinking tools.One of the systems thinking tools that is particularly useful in analysing major incidents and safety culture is causal loop diagrams. The diagrams can be used to explain the systemic structure sustaining a safety culture and identify effective interventions to improve the safety culture and prevent a recurrence of a major incident. The paper demonstrates the use of systems thinking and causal loop diagrams through a case study on Bellevue hazardous waste fire in Western Australia. The case study shows how different actors in the system, each acting in reaction to pressures that they are facing, produced and sustained a poor safety culture that was a major contributory factor to the fire in 2001.     

An adaptive management system for hazardous technology organizations

This paper introduces a management system suitable for hazardous technology organizations which has been developed based on the assumptions that in these organizations safety is a critical strategic factor, the existence of an enhanced safety culture is a crucial condition for safety and that safety culture enhancement implies in organizational changes. The management system was theoretically developed and then implemented at a Brazilian nuclear research and development installation, as a case study, in order to validate the theoretical propositions assumed in the system development. The developed management system comprises a day-to-day based organizational framework which treats safety as one of the organization strategic perspectives and provides a continuous adaptation of the complex causal inter-relationships which occur between the implementation of new management practices – designed and implemented according to the requirements of the criteria of excellence of the Brazilian quality award management assessment model – and the organization safety culture. The results achieved in the case study permitted to demonstrate the validness of all the system theoretical propositions and to conclude that the continuous and systematic operation of the management system makes an effective safety culture enhancement possible and simultaneously facilitates that the new management practices be effectively implemented, thus making continuous organizational improvement possible.     

Managers’ conceptions regarding human factors in air traffic management and in airport operations

Human factors (HF) in creating and managing safety in complex systems is a continuous topic of research and discussion. In the aviation organisation under study here, an HF expert had started work in a newly created position one and a half years prior to the study. The aim of the study was to find out if HF was seen as a safety creating factor and what the conceptions of HF were in regard to the theoretical developments in the field. These topics were studied in order to determine the most effective means of implementing HF-work within the organisation. Two manager groups (upper and middle management) were targeted as subjects of the study due to their crucial role in developing working culture. Twenty-one managers were interviewed from nine units that represented three operational environments (radar units with heavy traffic, combined civil/military units and procedural air traffic control units, including airport operations. Managers were found to have disjointed and vague conceptions of HF and a lack of shared vision or strategy regarding HF. Some managers lacked an appropriate conception of HF. The present situation can prevent the organisation from utilizing HF competence in maintaining and developing the safety of services. Conceptions were most up-to-date at units, where outside pressures for change had forced managers to take HF issues into account in their operational environments. While the long-term implementation of HF faces considerable challenges, the article gives several proposals for organisational structures that support a more effective realization of HF.     

Safety culture and the issue of power

Issues of power and conflict in organizations are rarely addressed in safety culture research. Much safety culture research thus rests upon a harmony model of organizational life. This, it is argued, is a fundamental shortcoming of the existing research. The article discusses the relationship between power-oriented and cultural approaches to organizational safety. The accident with space shuttle Challenger is used as a case, since this accident has been analysed through both approaches.The article argues that issues of culture and power are so intertwined that safety culture research should incorporate perspectives of power and conflict. This is necessary in order to be able to give a realistic account of the dynamics of organizational life. Introducing a more power-oriented view on safety culture can also serve as the basis for important ethical considerations regarding the improvement of safety culture.Finally, it is argued that a safe culture is not necessarily one which is homogenous and free from conflict. Having conflicting views on safety can in fact be a safety resource by serving as a kind of requisite variety that facilitates learning.