Reliable or Resilient: Recovery from the Unanticipated

摘要

The increased complexity of infrastructural and transportation systems makes those systems less tractable, requiring new notions for reliability, control over operational performance and safety assessment. To this purpose, the contribution elaborates on the principles offered by the Cynefin notion as a guide in landscaping system complexity and dynamics. Beyond the normal and predictable behavior of operators by mathematical assessment of their reliability and procedural control over safe performance of the operator, this contribution emphasizes two new approaches. The scope of this study is to reconsider the notion of human error as an adequate operator response to system failure under a variety of operating conditions. It introduces operator variance, resilience and transitions across system states and mental modes as an operationalization of the notion of Good Airmanship and Good Seamanship. On one hand a design oriented expansion of the safety envelope with respect to resilience is argued, while during operations at the performance level of the operator, the conventional Skill-Rule-Knowledge based model of Rasmussen is adapted, adding a intrapersonal reflex level and a interpersonal crew coordination level. Such an augmented ability to recover from the unanticipated is demonstrated for the aviation sector.