Towards increased reliability by objectification of Hazard Analysis and Risk Assessment (HARA) of automated automotive systems

Hazard Analysis and Risk Assessment (HARA) in various domains like automotive, aviation, process industry etc. suffer from the issues of validity and reliability. While there has been an increasing appreciation of this subject, there have been limited approaches to overcome these issues. In the automotive domain, HARA is influenced by the ISO 26262 international standard which details functional safety of road vehicles. While ISO 26262 was a major step towards analysing hazards and risks, like other domains, it is also plagued by the issues of reliability. In this paper, the authors discuss the automotive HARA process. While exposing the reliability challenges of the HARA process detailed by the standard, the authors present an approach to overcome the reliability issues. The approach is obtained by creating a rule-set for automotive HARA to determine the Automotive Safety Integrity Level (ASIL) by parametrizing the individual components of an automotive HARA, i.e., severity, exposure and controllability. The initial rule-set was put to test by conducting a workshop involving international functional safety experts as participants in an experiment where rules were provided for severity and controllability ratings. Based on the qualitative results of the experiments, the rule-set was re-calibrated. The proposed HARA approach by the creation of a rule- set demonstrated reduction in variation. However, the caveat lies in the fact that the rule-set needs to be exhaustive or sufficiently explained in order to avoid any degree of subjective interpretation which is a source of variation and unreliability

Towards an analytics and an ethics of expertise: Learning from decision aiding experiences in public risk assessment and risk management

Public expertise in safety, security and environment is a process that is increasingly submitted to control and transparency. It therefore requires an oversight, a monitoring and an aiding approach on its conduct and its governance. Difficulties learned from experiences in framing risk problems and sharing expertise conclusions and recommendations are pointed. Our practice of expertise has made clear to us that "expertise is a decision aiding process for a decision-maker which contains other decision aiding processes for the experts involved. To overcome this paradox, we argue on the need of a generic integrated framework for expertise that allows framing a valid and a legitimate expertise process and conclusions. Public expertise is then defined and mai

Perception of risk in construction. Exploring the factors that influence experts in occupational health and safety.

Risk perception is studied in many research disciplines. Although many of the factors that influence the perception of risk in the field of occupational risk prevention are known, there is still no complete understanding of the ways in which professionals in this sector perceive risks. This study analyzes the incidence of sociodemographic variables (gender, age, university degree, seniority of the qualification and professional experience) in the perception of the probability and consequences of accident risk of a group of Construction Safety and Health Experts. Additionally, the incidence of these variables has been evaluated in various stages of a construction. On the basis of a questionnaire survey of 30 construction processes, and applying a linear multilevel regression model, statistically significant differences in perceived risk were obtained depending on the age of the Construction Safety Experts, while it was determined that there is no significant difference in the perception of risk between men and women in this professional sector. Greater discrepancies were found when evaluating the overall risk of construction activities in the early stages of a construction site. Nevertheless, in spite of the sociodemographic differences between Construction Safety Experts, we conclude that their risk assessments are highly coherent

Tools and Techniques in Risk Assessment in Public Risk Management Organisations

Risk assessment and the knowledge provided through this process is a crucial part of any decision-making process in the management of risks and uncertainties. Failure in assessment of risks can cause inadequacy in the entire process of risk management, which in turn can lead to failure in achieving organisational objectives as well as having significant damaging consequences on populations affected by the potential risks being assessed. The choice of tools and techniques in risk assessment can influence the degree and scope of decision-making and subsequently the risk response strategy. There are various available qualitative and quantitative tools and techniques that are deployed within the broad process of risk assessment. The sheer diversity of tools and techniques available to practitioners makes it difficult for organisations to consistently employ the most appropriate methods. This tools and techniques adaptation is rendered more difficult in public risk regulation organisations due to the sensitive and complex nature of their activities. This is particularly the case in areas relating to the environment, food, and human health and safety, when organisational goals are tied up with societal, political and individuals’ goals at national and international levels. Hence, recognising, analysing and evaluating different decision support tools and techniques employed in assessing risks in public risk management organisations was considered. This research is part of a mixed method study which aimed to examine the perception of risk assessment and the extent to which organisations practise risk assessment’ tools and techniques. The study adopted a semi-structured questionnaire with qualitative and quantitative data analysis to include a range of public risk regulation organisations from the UK, Germany, France, Belgium and the Netherlands. The results indicated the public risk management organisations mainly use diverse tools and techniques in the risk assessment process. The primary hazard analysis; brainstorming; hazard analysis and critical control points were described as the most practiced risk identification techniques. Within qualitative and quantitative risk analysis, the participants named the expert judgement, risk probability and impact assessment, sensitivity analysis and data gathering and representation as the most practised techniques

Uncertainty in maritime risk analysis: Extended case study on chemical tanker collisions

Uncertainty is inherent to risk analysis. Therefore, it is extremely important to properly address the issue of uncertainty. In the field of risk analysis for maritime transportation systems, the effect of uncertainty is rarely discussed or quantified. For this reason, this article discusses a case study dealing with risk analysis for a chemical spill in the Gulf of Finland and analyses the related uncertainties by adopting a systematic framework. Risk is assessed in terms of the expected spill frequency and spill volumes caused by collisions between ships and chemical tankers in the Gulf of Finland. This is done by applying a collision consequence with a novel approach-to-collision-speed linkage model and Gulf of Finland-specific causation factors, which are based on reanalysing accident data. This article also presents a metamodel for assessing collision probability with initial vessel speeds for any given scenario where a chemical tanker is about to be struck by another vessel. Even when conducting a risk analysis using state-of-the-art methods, there is still a medium-high degree of uncertainty in the model presented in this article, which only becomes apparent when conducting a systematic uncertainty assessment analysis. However, an uncertainty assessment is an important part of quantitative maritime risk analysis. For this purpose, a qualitative framework for uncertainty assessment analysis is introduced for general use in the field of maritime risk analysis.</p

Forecasts or fortune-telling : when are expert judgements of safety risk valid?

Safety analysis frequently relies on human estimates of the likelihood of specific events. For this purpose, the opinions of experts are given greater weight than the opinions of non-experts. Combinations of individual judgements are given greater weight than judgements made by a lone expert. Various authors advocate specific techniques for eliciting and combining these judgements. All of these factors – the use of experts, the use of multiple opinions, and the use of elicitation and combination techniques – serve to increase subjective confidence in the safety analysis. But is this confidence justified? Do the factors increase the actual validity of the analysis in proportion to the increase in subjective confidence? In this paper, by means of a critical synthesis of evidence from multiple disciplines, we argue that it is plausible that expert judgement deserves special standing, but only for well understood local causal mechanisms. We also conclude that expert judgements can be improved by using appropriate elicitation techniques, including by combining judgement from multiple experts. There is, however, no evidence to suggest that fuzzy algorithms, neural networks, or any other form of complicated processing of expert judgement have any advantage over simple combination mechanisms

Testing automated driving systems to calibrate drivers’ trust

Automated Driving Systems (ADSs) offer many potential benefits like improved safety, reduced traffic congestion and lower emissions. However, such benefits can only be realised if drivers trust and make use of such systems. The two challenges explored in this thesis are: 1) How to increase trust in ADSs? 2) How to identify the test scenarios to establish the true capabilities and limitations of ADSs? Firstly, drivers’ trust needs to be calibrated to the “appropriate” level to prevent misuse (due to over trust) or disuse (due to under trust) of the system. In this research, a method to calibrate drivers’ trust to the appropriate level has been created. This method involves providing knowledge of the capabilities and limitations of the ADSs to the driver. However, there is a need to establish the capabilities and limitations of the ADSs which form the knowledge to be imparted to the driver. Therefore, the next research contribution lies in the development of a novel method to establish the knowledge of capabilities and limitations of ADSs (used to calibrate trust) in a reliable manner. This knowledge can be created by testing ADSs. However, in literature, an unanswered research question remains: How to identify test scenarios which highlight the limitations of ADSs? In order to identify such test scenarios, a novel hazard based testing approach to establish the capabilities and limitations of ADSs is presented by extending STPA (a hazard identification method) to create test scenarios. To ensure reliability of the hazard classification (and of the knowledge), the author created a novel objective approach for risk classification by creating a rule-set for risk ratings. The contribution of this research lies in developing a method to increase trust in ADSs by creating reliable knowledge using hazard based testing approach which identifies how an ADS can fail