This paper proposes an amendment of the classification of safety events based on their controllability and contemplates the potential of an event to escalate into higher severity classes. It considers (1) whether the end-user had the opportunity to intervene into the course of an event, (2) the level of end-user familiarity with the situation, and (3) the positive or negative effects of end-user intervention against expected outcomes. To examine its potential, we applied the refined classification to 296 aviation safety investigation reports. The results suggested that pilots controlled only three-quarters of the occurrences, more than three-thirds of the controlled cases regarded fairly unfamiliar situations, and the flight crews succeeded to mitigate the possible negative consequences of events in about 71% of the cases. Further statistical tests showed that the controllability-related characteristics of events had not significantly changed over time, and they varied across regions, aircraft, operational and event characteristics, as well as when fatigue had contributed to the occurrences. Overall, the findings demonstrated the value of using the controllability classification before considering the actual outcomes of events as means to support the identification of system resilience and successes. The classification can also be embedded in voluntary reporting systems to allow end-users to express the degree of each of the controllability characteristics so that management can monitor them over time and perform internal and external benchmarking. The mandatory reports concerned, the classification could function as a decision-making parameter for prioritising incident investigations.
Modern safety thinking and models focus more on systemic factors rather than simple cause-effect attributions of unfavourable events on the behaviour of individual system actors. This study concludes previous research during which we had traced practices of new safety thinking practices (NSTPs) in aviation investigation reports by using an analysis framework that includes nine relevant approaches and three safety model types mentioned in the literature. In this paper, we present the application of the framework to 277 aviation reports which were published between 1999 and 2016 and were randomly selected from the online repositories of five aviation authorities. The results suggested that all NSTPs were traceable across the sample, thus followed by investigators, but at different extents. We also observed a very low degree of using systemic accident models. Statistical tests revealed differences amongst the five investigation authorities in half of the analysis framework items and no significant variation of frequencies over time apart from the Safety-II aspect. Although the findings of this study cannot be generalised due to the non-representative sample used, it can be assumed that the so-called new safety thinking has been already attempted since decades and that recent efforts to communicate and foster the corresponding aspects through research and educational means have not yet yielded the expected impact. The framework used in this study can be applied to any industry sector by using larger samples as a means to investigate attitudes of investigators towards safety thinking practices and respective reasons regardless of any labelling of the former as “old” and “new”. Although NSTPs are in the direction of enabling fairer and more in-depth analyses, when considering the inevitable constraints of investigations, it is more important to understand the perceived strengths and weaknesses of each approach from the viewpoint of practitioners rather than demonstrating a judgmental approach in favour or not of any investigation practice.
In safety science and practice, there have been various safety models, each of them reflecting a particular approach to safety management and accident causality. The large variety of models suggested in literature and applied in practice serve the communication of diverse perspectives towards safety and the need to consider contextual factors, but it does not allow the establishment of a common language within and across organisations and industry sectors. Considering the potential benefits of talking a lingua franca when it comes to safety and inspired by the Standard Model used in particle physics and recent suggestions from relevant studies, we thought of exploring the possibility to introduce a Standard Safety Model (STASAM). As a first step, we focused on four representative safety and accident models widely used, discussed and debated: the Swiss Cheese Model, AcciMap, Functional Resonance Analysis Method (FRAM) and Systems-Theoretic Accident Model and Processes (STAMP). We reviewed literature which compares the particular models, and we listed the strengths and weaknesses of each as a means to set the grounds for the STASAM. The combinations of these models with a focus to host their advantages and avoiding their disadvantages led to a three-level STASAM. The concept STASAM was used in two random incident investigation reports to assess its applicability and visualisation against the original models. The results of the application along with the STASAM concept were reviewed by three safety professionals and three safety researchers. The comments received were in the positive direction and indicated the potential of establishing an inclusive and commonly accepted safety/accident model. The next research phase will be the additional review of the STASAM and its pilot application to a variety of safety events and systems as a means to test its reliability and strengthen its validity.
