Risk assessment in risk-informed decision-making: Foundations, challenges, and approaches
MetadataVis full innførsel
This PhD thesis clarifies foundational concepts and challenges in risk assessment and provides practical guidance for its performance and use in riskinformed decision-making (RIDM). The scope is delimited to engineering risk assessments of sociotechnical systems for informing strategic decisionmaking involving major accident risk to human, environmental, or material assets. Such decisions involve multiple objectives that must be balanced in light of information about the uncertainties and potential consequences of the alternative courses of action, and engage many stakeholders due to their wide-ranging impacts on individuals, societies, and ecologies. The overall objective of the PhD thesis is to develop basic theory and methods that support the planning, performance, and use of risk assessment in risk-informed decision-making. This objective is detailed in seven subobjectives that are addressed in seven corresponding articles. The articles have an interdisciplinary focus and research synthesis as the bearing methodology. The main contributions are: A mapping of foundational and contextual challenges to RIDM in the debate concerning future oil and gas development in Lofoten and Vesterålen in the north of Norway, analyzed in light of the Deepwater Horizon accident in 2010. A new framework for assessing complexity in risk assessment, consisting of a definition, a conceptual map, an ontological and epistemological position, a set of indicators, and a procedure for calculating a complexity index, , that can help to acknowledge, reduce, and describe complexity in the assessment. A new framework for assessing uncertainty in risk assessment, consisting of a definition and a questionnaire that can help to clarify and assess uncertainty as a premise and limitation in risk assessment.A new framework for assessing ambiguity in risk assessment, consisting of an overall definition and three sub-definitions of ambiguity, and a checklist that can be used to identify sources and manifestations of ambiguity in the assessment. An explanatory overview of the most common types of risk metrics and a set of evaluation criteria that can aid the discussion and choice of risk metrics. A stepwise procedure for RIDM and an overview of pitfalls at each step, which are translated into a set of quality criteria that can be used as a checklist for planning, performing, and reviewing the RIDM process.The new theories and methods clarify foundational issues that aect the role and value of risk assessment in RIDM and oer operational guidance for an analytic-deliberative approach to risk assessment. The aim of such an approach is to integrate science (analysis) and discussion (deliberation), by involving decision-makers and stakeholders in the risk assessment to ensure that it produces sound and relevant information. A driving motivation for this PhD thesis is that improving risk assessment for RIDM applications presupposes foundational insight. The academic and practical significance of the thesis are therefore closely related. The academic relevance of the thesis resides in the clarification of foundational issues that riddle the scientific community, and the comprehensive synthesis of past, present, and future foci of interdisciplinary RIDM research. The new theories and methods enable clarification and reconciliation of conflicting perspectives, which are necessary for cumulative development and theory building across dierent stances in the risk assessment community. The main message to fellow academics is the importance of acknowledging the premises and limitations of the perspectives they employ. The practical utility of the thesis resides in the provision of a comprehensive basis for discussion in an analytic-deliberative approach to risk assessment. In particular, it can help risk analysts to elicit and translate needs of decision-makers and stakeholders into analytical requirements and assumptions. It can also help decision-makers and stakeholders to articulate their expectations for the risk assessment and interpret the results in light of the decision objectives. The main message to practitioners is the importance of clarifying foundational issues in a structured, holistic, and transparent approach to risk assessment and RIDM. In conclusion, this thesis contributes to advancing theory and applications, by promoting a more conscientious approach to risk assessment and a holistic understanding of its potentials and limitations for informing decisionmaking. Further research is, however, necessary for testing and enhancing the utility of the new theories and methods.