*1.1. Systematic Literature Review*

The primary reason for conducting a systematic review was to examine how learning from incidents occurs in aircraft maintenance and continuing airworthiness management. Other sectors and the issues impacting learning in these areas were also considered. The literature review sets out to establish factors that contribute to or potentially constrain learning from incidents in the subject domain. Applying a qualitative research approach is advantageous as it can provide a deeper contextual understanding of the literature and can assist with better research integration. The application of rigor and comprehensiveness can assist with advancing knowledge and identifying research gaps and aspects for further research in this area. Okoli and Schabram [20] sugges<sup>t</sup> "a dedicated methodological approach is necessary in any kind of literature review". A preliminary search of literature highlighted a scarcity of best-practice guidelines for conducting systematic literature reviews in this area.

Qualitative research involves handling considerable volumes of data and a degree of discipline is required so that search results, decisions regarding subject inclusions and exclusions are recorded and references are well managed. Endnote was used in support of the literature review during this research. An electronic database is useful for supporting a search strategy, arranging publications and storing references [21]. The qualitative data analysis software NVivo (NVivo 12, QSR International, Melbourne, Australia) was used to augmen<sup>t</sup> the data management, storage and analysis associated with the literature review. NVivo possesses many functions, such as facilitating the synthesis of a review [22]. A systematic search of in excess of 1000 publications was performed in the following databases: Web of Science, Scopus, IEEE Xplore, ProQuest and EBSCO. The following predefined search terms were applied: "learning

from incidents", "learning from experience", "aircraft maintenance", "aircraft management" and "safety managemen<sup>t</sup> systems". A practical screening of title and abstract was applied to each manuscript using predefined terms (e.g., subject, setting, publication, year). This part of the process had to be broad enough to create a sufficient number of applicable publications but also had to be practically manageable. The following criteria were implemented for the practical screening of the source bibliographic details, title and abstract:


The output of the practical screen step produced a list of publications denoted as the screened set of publications. An Endnote library was then created to store and manage the full text of the retrieved publications. The next step involved filtering the publications into primary and secondary publication subsets using only primary research manuscripts in the next phase. Applying a set of criteria helps to reduce any researcher bias in the screening system. A set of inclusion and exclusion criteria [23] was developed in accordance with the guidelines included in [24,25], listed in Table 1. Two researchers were involved in the screening process.



The final set of 18 papers was imported into NVivo and the following analysis approach, as defined by Bandara et al. [22], was used for the selection of the codification themes:


NVivo is limited in terms of providing thematic classifications based on the occurrence of key words but can assist with identifying relationships between words and phrases amongs<sup>t</sup> publications. It also provided thematic classifications of data based on the occurrence of key words and phrases. The coding process consisted of selecting relevant passages of text that were captured in one or several of the framework nodes. Maykut and Morehouse [26] defines a propositional statement as "a statement of fact the researcher tentatively proposes, based on the data". Memos were used to draft these summary statements which formed part of the literature review. Central to the idea of learning is how an incident is generally moderated during its useful existence. Section 1.2 documents this approach.

### *1.2. The Notion of a Generic Incident Lifecycle*

Figure 1 illustrates how an incident tends to be managed through its quiddity. This view is one possible way of representing the elements comprising a lifecycle view. Cooke and Rohleder [27] sugges<sup>t</sup> it should also be evident that an incident system will operate most e ffectively when a safety managemen<sup>t</sup> system has already been put in place and avoidable risks are addressed. They propose an e ffective system that addresses: identification and response, reporting, investigation, identifying causal structure, making recommendations, communicating and recalling incident learning, and implementing corrective actions. Drupsteen et al. [28] also consider an incident from a learning perspective in its cycle. Their main constituents are investigating and analyzing incidents, planning interventions, intervening and evaluating (each of these four stages are further sub-divided into eleven sub-components). Continuing airworthiness-related incidents are notified by way of a formal mechanism of reporting. During the data gathering phase of this research, the steps outlined in Figure 1 were found to be dictated by regulatory requirements [6,8]. Once the incident enters its lifecycle, it ideally transverses a process that transforms the information gathered into knowledge. Figure 1 and the contiguous paragraph o ffer an overview of how the capture and processing of the incident information occurs in practice.

**Figure 1.** An example of an aviation incident lifecycle within the continuing airworthiness and aircraft maintenance sector.

Continuing airworthiness-related serious incidents are rare but often due to environmental, cognitive and mechanical demands, reportable and unreportable events do occur. All organizations in the industry segmen<sup>t</sup> subscribe to a reporting system and reports can be made electronically or in paper form in smaller organizations. The main underpinning regulation in Europe, EU regulation 2018/1139 [29], refers to a managemen<sup>t</sup> system and mandates an organization to implement and maintain such a system to ensure compliance with these essential requirements. In practice, although a reporter can report events directly to an aviation authority, all organizations are required to have an internal reporting system also. A focal point/gate keeper will process these reports either internally and/or inform third party stakeholders such as aviation authority or aircraft manufacturer as required by procedure. Depending on the event, technical managemen<sup>t</sup> may determine there are immediate actions required to recover a situation or restore serviceability. While a small number of scenarios will require an event to be investigated fully before an aircraft returns to service, many incidents are investigated post event. As soon as causation is established, if accepted by the relevant technical function, the report is closed. This managemen<sup>t</sup> system is strongly influenced by regulatory requirements and procedural form and is a pre-eminent influence on how an incident and its actors behave from the time a report is made to the time its impact has been terminated. One of the limitations inherent in this cycle is that lessons tend to be delivered at a later point in time mostly through the medium of recurrent training programs such as continuation and human factors training.

Therefore, there is often a hiatus in the feedback cycle. However, the e ffectiveness of the process and the perceived contribution to learning are not fully reflected in this view.

### *1.3. A Potential Learning Cycle Emerges*

According to Lindberg et al. [30], in order to prevent accidents, it is essential to learn from previous accidents and incidents. Lukic et al. [31] sugges<sup>t</sup> that in order to increase the e ffectiveness of learning from incidents, it is necessary to understand who should be included in the learning process. In Figure 2, the incident lifecycle is aligned with the learning process in order to highlight where potential improvements might be made. As the incident is managed and causation is established, there are potential avenues open for learning. The ultimate desired outcome is that adequate measures are put in place to prevent a recurrence of the event. However, the lessons available in a potential learning product are not always used to best e ffect when considering the Figure 1 process. Drupsteen et al. [28] state that "many incidents occur because organizations fail to learn from past lessons", because the traditional approach often stops short of preventing future incidents. Their research examines: investigating and analyzing incidents, planning and prevention, intervening and evaluating steps in a learning process. Ward et al. [15] found that the resulting relationship between the individuals and the systems have a direct impact upon the system and prevailing environment. Silva et al. [3] examined how organizations use accident information to reduce the occurrence of unwelcome events. Drupsteen and Wybo [10] found that hindsight can determine if an organization did learn from an event but there are no models to assist with gauging the "propensity" of an organization to learn. Drupsteen and Hasle [1] sugges<sup>t</sup> that learning can be improved if limiting factors are addressed.

**Figure 2.** Incident learning product and process (broken line denotes iterative learning feedback).

The proposed enhancement (shown in Figure 2) to the generic lifecycle in the "traditional" approach represents a novel view and brings the learning product into focus. This figure highlights the benefits of ensuring the feedback loop of an incident is centered on the learning product. Treating its development as an iterative process ensures all steps in the cycle are included and where deficiencies are noted, they can be identified and communicated during the iterations. This can assist with delivery of timely and sustainable learning and help prevent an inability to think, talk and see what actions are proper in specific situations [32]. According to Drupsteen et al. [28], it is necessary to gain an insight into the steps of the process to identify factors that hinder learning in order to make improvements. The research suggests an emphasis on accessible, timely and appropriate learning content could provide all stakeholders in the process with better value for their e fforts. Perhaps one reason that the customary incident lifecycle and its limitations prevail is related to managemen<sup>t</sup> theory. While innovators like Taylor [33] are responsible for advances in management, such theories have not always fully considered safety and learning. The

early 1900s witnessed a time when it was necessary to inaugurate e fficiencies in production by initially decomposing tasks in order to introduce liner e fficiencies. The limitations experienced in incident learning processes today may relate to this circumscribed tradition.
