Zoekresultaten

Review of existing aviation safety metrics

Exploring the diversity in safety measurement practices

A literature review, which was conducted during the research project “Measuring Safety in Aviation – Developing Metrics for Safety Management Systems”, identified several problems and challenges regarding safety performance metrics in aviation. The findings from this review were used to create a framework for interviewing 13 companies in order to explore how safety performance is measured in the industry. The results from the surveys showed a wide variety of approaches for assessing the level of safety. The companies encounter and/or recognise problematic areas in practice when implementing their safety management. The findings from the literature review are partially confirmed and it seems that the current ways of measuring safety performance are not as straight forward as it might be assumed. Further research is recommended to explore alternative methods for measuring aviation safety performance.

Critical review of safety performance metrics

Various tools for safety performance measurement have been introduced in order to fulfil the need for safety monitoring in organisations, which is tightly related to their overall performance and achievement of their business goals. Such tools include accident rates, benchmarking, safety culture and climate assessments, cost-effectiveness studies, etc. The current work reviews the most representative methods for safety performance evaluation that have been suggested and applied by a variety of organisations, safety authorities and agencies. This paper discusses several viewpoints of the applicability, feasibility and appropriateness of such tools, based on the viewpoints of managers and safety experts involved in a relevant research that was conducted in a large aviation organisation. The extensive literature cited, the discussion topics, along with the conclusions and recommendations derived, might be considered by any organisation that seeks a realistic safety performance assessment and establishment of effective measurement tools.

Measuring safety in aviation

As part of their SMS, aviation service providers are required to develop and maintain the means to verify the safety performance of their organisation and to validate the effectiveness of safety risk controls. Furthermore, service providers must verify the safety performance of their organisation with reference to the safety performance indicators and safety performance targets of the SMS in support of their organisation’s safety objectives. However, SMEs lack sufficient data to set appropriate safety alerts and targets, or to monitor their performance, and no other objective criteria currently exist to measure the safety of their operations. The Aviation Academy of the Amsterdam University of Applied Sciences therefore took the initiative to develop alternative safety performance metrics. Based on a review of the scientific literature and a survey of existing safety metrics, we proposed several alternative safety metrics. After a review by industry and academia, we developed two alternative metrics into tools to help aviation organisations verify the safety performance of their organisations.The AVAV-SMS tool measures three areas within an organisation’s Safety Management System:• Institutionalisation (design and implementation along with time and internal/external process dependencies).• Capability (the extent to which managers have the capability to implement the SMS).• Effectiveness (the extent to which the SMS deliverables add value to the daily tasks of employees).The tool is scalable to the size and complexity of the organisation, which also makes it useful for small and medium-sized enterprises (SMEs). The AVAS-SCP tool also measures three areas in the organisation’s safety culture prerequisites to foster a positive safety culture:• Organisational plans (whether the company has designed/documented each of the safety cultureprerequisites).• Implementation (the extent to which the prerequisites are realised by the managers/supervisors acrossvarious organisational levels).• Perception (the degree to which frontline employees perceive the effects of managers’ actions relatedto safety culture).We field-tested these tools, demonstrating that they have adequate sensitivity to capture gaps between Work-as-Imagined (WaI) and Work-as-Done (WaD) across organisations. Both tools are therefore useful to organisations that want to self-assess their SMS and safety culture prerequisite levels and proceed to comparisons among various functions and levels and/or over time. Our field testing and observations during the turn-around processes of a regional airline confirm that significant differences exist between WaI and WaD. Although these differences may not automatically be detrimental to safety, gaining insight into them is clearly necessary to manage safety. We conceptually developed safety metrics based on the effectiveness of risk controls. However, these could not be fully field-tested within the scope of this research project. We recommend a continuation of research in this direction. We also explored safety metrics based on the scarcity of resources and system complexity. Again, more research is required here to determine whether these provide viable solutions.

Measuring safety in aviation

A literature review conducted as part of a research project named “Measuring Safety in Aviation – Developing Metrics for Safety Management Systems” revealed several challenges regarding the safety metrics used in aviation. One of the conclusions was that there is limited empirical evidence about the relationship between Safety Management System (SMS) processes and safety outcomes. In order to explore such a relationship, respective data from 7 European airlines was analyzed to explore whether there is a monotonic relation between safety outcome metrics and SMS processes, operational activity and demographic data widely used by the industry. Few, diverse, and occasionally contradictory associations were found, indicating that (1) there is a limited value of linear thinking followed by the industry, i.e., “the more you do with an SMS the higher the safety performance”, (2) the diversity in SMS implementation across companies renders the sole use of output metrics not sufficient for assessing the impact of SMS processes on safety levels, and (3) only flight hours seem as a valid denominator in safety performance indicators. At the next phase of the research project, we are going to explore what alternative metrics can reflect SMS/safety processes and safety performance in a more valid manner

Evaluating the horizontal alignment of safety management activities through cross-reference of data from safety audits, meetings and investigations

Vertical and horizontal alignment within organizations are seen as prerequisites for meeting strategic objectives and indications of effective management. In the area of safety management, the concept of vertical alignment has been followed through the introduction of hierarchical structures and bidirectional communication, but horizontal alignment has been given little attention. The principal goal of this study was the assessment of horizontal alignment within an aviation organization with the use of data from safety investigations, audits and meetings in order to explore the extent to which (1) causal factors recorded in safety investigation reports comprised topics discussed by safety committees and focus areas of internal safety auditors, and (2) the agendas of safety committees include weak points revealed during safety audits. The study employed qualitative and quantitative analysis of data collected over a 6 years’ period at three organizational levels. The results suggested a low horizontal alignment across the three pairs of the corresponding safety management activities within each organizational level. The findings were attributed to the inadequacy of procedures and lack of a safety information database for consistently sharing safety information, cultural factors and lack of planning for the coordination of safety management activities. The current research comprises a contribution to the literature and practice and introduces a technique to assess the intra-alignment of safety management initiatives within various organizational levels. Future research is needed in order to investigate the association between horizontal alignment of safety management practices and safety performance.