Improving risk characterisations in practical situations by highlighting knowledge aspects, with applications to risk matrices

- The paper presents a general framework for describing or characterising risk
- The characterisations highlight knowledge aspects of risk, including potential surprises
- Practical methods are reviewed and discussed, in particular extended risk matrices
- A method for criticality ranking of assumptions is presented
- Also a simple method for criticality ranking of risk (influencing) factors and
- An approach for describing the manageability of a measure (factor)

Current practice for risk characterisations is based on methods reflecting threats, their consequences and probability, as well as concepts like risk factors and sources. The risk matrix is an example of such a method. The risk analysis field has demonstrated that there are many challenges related to this practice and there is a substantial potential for improvements in how the characterisations can be conducted. The key is to better reflect the knowledge aspect of risk. The purpose of the present paper is to present a set of practical methods that can be used for characterising risk in this setting in line with these findings of the risk analysis field. Extended risk matrix approaches are highlighted. These approaches include strength of knowledge judgements and rankings of risk factors and assumptions supporting the analysis. Special attention is given to potential surprises relative to the current knowledge. Simple examples are presented to illustrate the use of these methods and approaches.