Injury causation in the great outdoors: A systems analysis of led outdoor activity injury incidents

Despite calls for a systems approach to assessing and preventing injurious incidents within the led outdoor activity domain, applications of systems analysis frameworks to the analysis of incident data have been sparse. This article presents an analysis of 1014 led outdoor activity injury and near miss incidents whereby a systems-based risk management framework was used to classify the contributing factors involved across six levels of the led outdoor activity ‘system’. The analysis identified causal factors across all levels of the led outdoor activity system, demonstrating the framework's utility for accident analysis efforts in the led outdoor activity injury domain. In addition, issues associated with the current data collection framework that potentially limited the identification of contributing factors outside of the individuals, equipment, and environment involved were identified. In closing, the requirement for new and improved data systems to be underpinned by the systems philosophy and new models of led outdoor activity accident causation is discussed.     

Understanding the human factors contribution to railway accidents and incidents in Australia

Forty rail safety investigation reports were reviewed and a theoretical framework (the Human Factors Analysis and Classification System; HFACS) adopted as a means of identifying errors associated with rail accidents/incidents in Australia. Overall, HFACS proved useful in categorising errors from existing investigation reports and in capturing the full range of relevant rail human factors data. It was revealed that nearly half the incidents resulted from an equipment failure, most of these the product of inadequate maintenance or monitoring programs. In the remaining cases, slips of attention (i.e. skilled-based errors), associated with decreased alertness and physical fatigue, were the most common unsafe acts leading to accidents and incidents. Inadequate equipment design (e.g. driver safety systems) was frequently identified as an organisational influence and possibly contributed to the relatively large number of incidents/accidents resulting from attention failures. Nearly all incidents were associated with at least one organisational influence, suggesting that improvements to resource management, organisational climate and organisational processes are critical for Australian accident and incident reduction. Future work will aim to modify HFACS to generate a rail-specific framework for future error identification, accident analysis and accident investigation.     

Operator error and system deficiencies: Analysis of 508 mining incidents and accidents from Queensland, Australia using HFACS

Historically, mining has been viewed as an inherently high-risk industry. Nevertheless, the introduction of new technology and a heightened concern for safety has yielded marked reductions in accident and injury rates over the last several decades. In an effort to further reduce these rates, the human factors associated with incidents/accidents needs to be addressed. A modified version of the Human Factors Analysis and Classification System was used to analyze incident and accident cases from across the state of Queensland to identify human factor trends and system deficiencies within mining. An analysis of the data revealed that skill-based errors were the most common unsafe act and showed no significant differences across mine types. However, decision errors did vary across mine types. Findings for unsafe acts were consistent across the time period examined. By illuminating human causal factors in a systematic fashion, this study has provided mine safety professionals the information necessary to reduce mine incidents/accidents further.     

Organisational accidents investigation methodology and lessons learned

The purpose of this paper is to reflect on accident analysis methods. As the understanding of industrial accidents and incidents has evolved, they are no longer considered as the sole product of human and/or technical failures but also as originating in an unfavourable organisational context. After presenting some theoretical developments which are responsible for this evolution, we will propose two examples of organisational accidents and incidents. We will then present some properties of organisational accidents, and we will focus on some "accident-generating" organisational factors. The definition of these factors comes from an empirical approach to event analysis. Finally, we will briefly present their implications for accident and incident analysis.     

Evaluation and optimization of chromium removal from tannery effluent by microemulsion in the Morris extractor

A multidisciplinary Road Accident Analysis Group with the objective of conducting in-depth investigations of specific types of accidents has existed in Denmark for some years. The group has analysed head-on collisions, left-turn accidents, truck accidents and single vehicle accidents. The data collection included police reports, the group's investigation of accident sites and vehicles involved, and interviews with the involved road users and witnesses. The main accident factors in the head-on collisions and in the single vehicle accidents were excessive speed, drunk driving and driving under the influence of illegal drugs. The primary accident factors in left-turn accidents were attention errors or misjudging the amount of time available to complete the left turn. In the truck accidents insufficient searching for visual information as well as speeding were major factors. For all the accident themes the primary injury factor was failure to wear seat- belts. The multidisciplinary approach has provided a rather precise knowledge of the contributing factors leading up to the accident. The method requires a lot of resources, which is a limiting factor for the number of accidents to be analysed in this way. However, the method is suitable for analysis of common occurring or very serious types of accidents.     

The railway accident of Eschede – technical background

In 1998 a very severe railroad accident occurred in Germany. The case went to court for negligent homicide after a preliminary investigation had been performed. The accident had been caused by fracture of a wheel and the manufacturer of the wheel and the railroad company were accused. The defendants engaged a number of experts to investigate the different technical aspects of the accident for their defence. In spring 2003 the court decided to employ an unique procedure, to hear all experts consecutively to get the best possible overview of the different opinions and possibly find the real cause of the accident. After the court had heard the testimony of these 13 experts from 5 different countries it decided to discontinue the case since the guilt of the accused was deemed to be very small, if there was any guilt at all and that further technical investigations and expert testimony would most probably bring the court no nearer to a conviction. A failure analysis proper was not the subject of the court procedure and therefore a complete investigation was not carried out. The result of the hearing was in the opinion of most experts, that the accident could not be explained by the results of the investigations performed. Rather a singular incident or technological material phenomenon could have initiated the fatigue crack, which then caused the accident. Since all realistic aspects of the accident had been thoroughly investigated by the experts, only speculations on such incidents or phenomena were possible.     

Accident investigation reporting deficiencies related to organizational factors in machinery space fires and explosions

Careful accident investigation provides opportunities to review safety arrangements in socio-technical systems. There is consensus that human intervention is involved in the majority of accidents. Ever cautious of the consequences attributed to such a claim vis-à-vis the apportionment of blame, several authors have highlighted the importance of investigating organizational factors in this respect. Specific regulations to limit what were perceived as unsuitable organizational influences in shipping operations were adopted by the International Maritime Organization (IMO). Guidance is provided for the investigation of human and organizational factors involved in maritime accidents. This paper presents a review of 41 accident investigation reports related to machinery space fires and explosions. The objective was to find out if organizational factors are identified during maritime accident investigations. An adapted version of the Human Factor Analysis and Classification System (HFACS) with minor modifications related to machinery space features was used for this review. The results of the review show that organizational factors were not identified by maritime accident investigators to the extent expected had the IMO guidelines been observed. Instead, contributing factors at the lower end of organizational echelons are over-represented.     

Multidisciplinary in-depth investigations of head-on and left-turn road collisions

To enhance traffic safety, a multidisciplinary Road Accident Investigation Team was established in Denmark for a 2-year trial period. The objective was to conduct in-depth investigations of specific types of accidents, and to identify effective preventive measures. The team consisted of a road engineer, a vehicle inspector, a police superintendent, a psychologist and a physician. Seventeen serious head-on collisions as well as 17 left-turn collisions were analysed. In collecting data, police reports were supplemented by the team's investigation of accident sites and vehicles involved, and interviews were carried out with the involved road users and witnesses. The drivers, to whom the accident factors were primarily related in the head-on collisions, were characterised by their conscious risk-taking behaviour. They were all males; several of them were under age 40 and had earlier traffic and/or drug convictions. The main accident factors were excessive speed, drunk driving and driving under the influence of illegal drugs. In the left-turn accidents, the most common accident factors were attention errors, and it was also noted that elderly drivers ( > 74) were over-represented. The synergy effect of working as a multidisciplinary team proved fruitful. It resulted in a more precise knowledge of the road accident circumstances and of contributing factors leading up to the accidents. Due to the great demand on resources, only a limited number of accidents could be analysed, but the results provide a basis for further and more targeted research.     

An analysis of the severity and incident duration of truck-involved freeway accidents

Data associated with over 9000 accidents involving large trucks and combination vehicles during a two-year period on freeways in the greater Los Angeles area are analyzed relative to collision factors, accident severity, and incident duration and lane closures. Relationships between type of collision and accident characteristics are explored using log-linear models. The results point to significant differences in several immediate consequences of truck-related freeway accidents according to collision type. These differences are associated both with the severity of the accident, in terms of injuries and fatalities, as well as with the impact of the accident on system performance, in terms of incident duration and lane closures. Hit-object and broadside collisions were the most severe types in terms of fatalities and injuries, respectively, and single-vehicle accidents are relatively more severe than two-vehicle accidents. The durations of accident incidents were found to be log-normally distributed for homogeneous groups of truck accidents, categorized according to type of collision and, in some instances, severity. The longest durations are typically associated with overturns.     

A holistic approach for assessing traffic safety in the United Arab Emirates

Traffic accident and fatality rates can be utilized as indicators of traffic safety, but cannot reflect the overall status of traffic safety in a country. This paper uses a holistic perspective approach to investigate traffic safety in the United Arab Emirates (UAE). Initially, 12 potential items were selected to investigate the issue of traffic safety in the country. The investigation included data collection and analyses from official police reports, survey among road-users and interview of traffic safety experts. Based on data analysis and interpretation, the main factors affecting traffic safety in the UAE along with their level of deficiency were identified. The study revealed that the main factors contributing to traffic safety in the UAE are driving behaviour, awareness, education and training, infrastructure, vehicle, law enforcement, coordination and quality of resources. Among these factors, a major deficiency was found in the “driving behaviour”, a minor deficiency in “vehicle safety”, and a moderate deficiency in the others. Based on the deficiency level of the factors recommendations were proposed to improve the status of traffic safety in the country.     

Accident prediction model for railway-highway interfaces

Considerable past research has explored relationships between vehicle accidents and geometric design and operation of road sections, but relatively little research has examined factors that contribute to accidents at railway-highway crossings. Between 1998 and 2002 in Korea, about 95% of railway accidents occurred at highway-rail grade crossings, resulting in 402 accidents, of which about 20% resulted in fatalities. These statistics suggest that efforts to reduce crashes at these locations may significantly reduce crash costs. The objective of this paper is to examine factors associated with railroad crossing crashes. Various statistical models are used to examine the relationships between crossing accidents and features of crossings. The paper also compares accident models developed in the United States and the safety effects of crossing elements obtained using Korea data. Crashes were observed to increase with total traffic volume and average daily train volumes. The proximity of crossings to commercial areas and the distance of the train detector from crossings are associated with larger numbers of accidents, as is the time duration between the activation of warning signals and gates. The unique contributions of the paper are the application of the gamma probability model to deal with underdispersion and the insights obtained regarding railroad crossing related vehicle crashes.     

Have we reached the organisational ceiling? a review of applied accident causation models,methods and contributing factors in construction

Work-related fatalities continue to represent a significant issue within the construction industry. Contemporary accident causation models are underpinned by systems thinking, however, it is unclear whether these theories have translated into the construction domain. This article presents the findings of a review that was conducted to determine if the construction accident analysis literature has applied a systems thinking approach to understand accident causation. Specifically, the review examined two key aspects: first the types of models and methods that have been applied to analyse construction incidents, and second, the types of contributing factors identified as playing a role in construction incidents. The findings are summarised using Rasmussen’s Risk Management Framework. The review revealed that contemporary models of accident causation have not yet been applied in construction-related research. It is concluded that the models and methods applied in the construction literature predominantly identify contributing factors associated with the company, management, and frontline work levels of the system, rather than considering broader, system-wide factors. Further, the relationships between individuals and organisations operating at each level of the system have not been typically examined. Further research underpinned by systems thinking is required to better understand accident causation in the construction domain.

• Highlights

• The review revealed that contemporary models of accident causation have not yet been applied in construction-related research;

• The models and methods applied in the construction literature predominantly identify contributing factors associated with the company, management, and front line work levels of the system, rather than considering broader, system-wide factors;

• Relationships between individuals and organisations operating at each level of the system have not yet been examined;

• Despite the efforts of regulators and construction entities, the consistently high rate of fatal accidents in construction highlights the challenges surrounding the practical management of safe production within complex and dynamic working environments;

• Accident analysis methods used in this industry have not kept pace with advances in the field of safety science.

     

Content analysis of 100 consecutive media reports of amusement ride accidents

Accident investigations influence public perceptions and safety management strategies by determining the amount and type of information learned about the accident. To examine the factors considered in investigations, this study used a content analysis of 100 consecutive media reports of amusement ride accidents from an online media archive. Fatalities were overrepresented in the media dataset compared with U.S. national estimates. For analysis of reports, a modified "Haddon matrix" was developed using human-factors categories. This approach was useful to show differences between the proportions and types of factors considered in the different accident stages and between employee and rider accidents. Employee injury accounts primarily referred to the employee's task and to the employee. Rider injury reports were primarily related to the ride device itself and rarely referred to the rider's "task", social influences, or the rider's own actions, and only some reference to their characteristics. Qualitatively, it was evident that more human factors analysis is required to augment scant pre-failure information about the task, social environment, and the person, to make that information available for prevention of amusement ride accidents. By design, this study reflected information reported by the media. Future work will use the same techniques with official reports.     

Modeling secondary accidents identified by traffic shock waves

The high potential for occurrence and the negative consequences of secondary accidents make them an issue of great concern affecting freeway safety. Using accident records from a three-year period together with California interstate freeway loop data, a dynamic method for more accurate classification based on the traffic shock wave detecting method was used to identify secondary accidents. Spatio-temporal gaps between the primary and secondary accident were proven be fit via a mixture of Weibull and normal distribution. A logistic regression model was developed to investigate major factors contributing to secondary accident occurrence. Traffic shock wave speed and volume at the occurrence of a primary accident were explicitly considered in the model, as a secondary accident is defined as an accident that occurs within the spatio-temporal impact scope of the primary accident. Results show that the shock waves originating in the wake of a primary accident have a more significant impact on the likelihood of a secondary accident occurrence than the effects of traffic volume. Primary accidents with long durations can significantly increase the possibility of secondary accidents. Unsafe speed and weather are other factors contributing to secondary crash occurrence. It is strongly suggested that when police or rescue personnel arrive at the scene of an accident, they should not suddenly block, decrease, or unblock the traffic flow, but instead endeavor to control traffic in a smooth and controlled manner. Also it is important to reduce accident processing time to reduce the risk of secondary accident.     

Augmenting defense-in-depth with the concepts of observability and diagnosability from Control Theory and Discrete Event Systems

Defense-in-depth is a fundamental principle/strategy for achieving system safety. First conceptualized within the nuclear industry, defense-in-depth is the basis for risk-informed decisions by the U.S. Nuclear Regulatory Commission, and is recognized under various names in other industries (e.g., layers of protection in the Chemical industry). Accidents typically result from the absence or breach of defenses or violation of safety constraints. Defense-in-depth is realized by a diversity of safety barriers and a network of redundancies. However, this same redundancy and the intrinsic nature of defense-in-depth - the multiple lines of defense or “protective layers” along a potential accident sequence - may enhance mechanisms concealing the occurrence of incidents, or that the system has transitioned to a hazardous state (accident pathogens) and that an accident is closer to being released. Consequently, the ability to safely operate the system may be hampered and the efficiency of defense-in-depth may be degraded or worse may backfire. Several accidents reports identified hidden failures or degraded observability of accidents pathogens as major contributing factors.In this work, we begin to address this potential theoretical deficiency in defense-in-depth by bringing concepts from Control Theory and Discrete Event Systems to bear on issues of system safety and accident prevention. We introduce the concepts of controllability, observability, and diagnosability, and frame the current understanding of system safety as a “control problem” handled by defense-in-depth and safety barriers (or safety constraints). Observability and diagnosability are information-theoretic concepts, and they provide important complements to the energy model of accident causation from which the defense-in-depth principle derives. We formulate a new safety-diagnosability principle for supporting accident prevention, and propose that defense-in-depth be augmented with this principle, without which defense-in-depth can degenerate into a defense-blind safety strategy. Finally, we provide a detailed discussion and illustrative modeling of the sequence of events that lead to the BP Texas City Refinery accident in 2005 and emphasize how a safety-diagnosable architecture of the refinery could have supported the prevention of this accident or mitigated its consequences. We hope the theoretical concepts here introduced and the safety-diagnosability principle become useful additions to the intellectual toolkit of risk analysts and safety professionals and stimulate further interaction/collaboration between the control and safety communities.     

System thinking applied to near misses: a review of industry-wide near miss reporting systems

Abstract

Learning from near misses is an important component of maintaining safe work systems. Within safety science it is widely accepted that a systems approach is the most appropriate for analysing incidents in sociotechnical systems. The aim of this article is to determine whether industry-level near miss reporting systems are consistent with systems thinking. Twenty systems were identified, from a range of work domains, and were evaluated against systems thinking-based criteria. While none of the reporting systems fulfilled the full set of criteria, all are able to identify actors and contributing factors proximal to events in sociotechnical systems and many capture information on how accidents were prevented. It is concluded that the explanatory power of near miss reporting systems is limited by the systems currently used to gather data. The article closes by outlining a research agenda designed to ensure that near miss reporting systems can fully align with the systems approach.     

Best practices in incident investigation in the chemical process industries with examples from the industry sector and specifically from Nova Chemicals

This paper will summarize best practices in incident investigation in the chemical process industries and will provide examples from both the industry sector and specifically from NOVA Chemicals. As a sponsor of the Center for Chemical Process Safety (CCPS), an industry technology alliance of the American Institute of Chemical Engineers, NOVA Chemicals participates in a number of working groups to help develop best practices and tools for the chemical process and associated industries in order to advance chemical process safety. A recent project was to develop an update on guidelines for investigating chemical process incidents. A successful incident investigation management system must ensure that all incidents and near misses are reported, that root causes are identified, that recommendations from incident investigations identify appropriate preventive measures, and that these recommendations are resolved in a timely manner. The key elements of an effective management system for incident investigation will be described. Accepted definitions of such terms as near miss, incident, and root cause will be reviewed. An explanation of the types of incident classification systems in use, along with expected levels of follow-up, will be provided. There are several incident investigation methodologies in use today by members of the CCPS; most of these methodologies incorporate the use of several tools. These tools include: timelines, sequence diagrams, causal factor identification, brainstorming, checklists, pre-defined trees, and team-defined logic trees. Developing appropriate recommendations and then ensuring their resolution is the key to prevention of similar events from recurring, along with the sharing of lessons learned from incidents. There are several sources of information on previous incidents and lessons learned available to companies. In addition, many companies in the chemical process industries use their own internal databases to track recommendations from incidents and to share learnings internally.     

Analysis of traffic accident injury severity on Spanish rural highways using Bayesian networks

Several different factors contribute to injury severity in traffic accidents, such as driver characteristics, highway characteristics, vehicle characteristics, accidents characteristics, and atmospheric factors. This paper shows the possibility of using Bayesian Networks (BNs) to classify traffic accidents according to their injury severity. BNs are capable of making predictions without the need for pre assumptions and are used to make graphic representations of complex systems with interrelated components. This paper presents an analysis of 1536 accidents on rural highways in Spain, where 18 variables representing the aforementioned contributing factors were used to build 3 different BNs that classified the severity of accidents into slightly injured and killed or severely injured. The variables that best identify the factors that are associated with a killed or seriously injured accident (accident type, driver age, lighting and number of injuries) were identified by inference.