Adopting an objective approach to criticality assessment: Learning from the past

Criticality assessment has been widely used in considering resource securement strategies. However, the selection and aggregation of the various risk factors remain a major challenge because these largely depend on subjective judgment by the evaluator. Therefore, it is necessary to introduce an objective perspective, which would develop criticality assessment as a more practical decision-making tool in combination with past subjective approaches. As a first attempt at an objective approach, this study conducted a case-based analysis of 448 supply disruption events for 22 metals. The results indicate 19 categories of causation of disruption, in which accidents, strikes, a fall in metal prices, natural disasters, and policy disputes are dominant. The analyses also reveal the differences in influential risk component between metals and supplier countries. For example, a fall in the metal price has more impact on developed supplier countries than developing countries. The knowledge gained from this case-based approach is useful in highlighting the risk components that have been overlooked in past assessments, in quantifying the integrated risk considering the relative importance of risk components, and in exploring strategies for criticality mitigation.