Complexity,Tight–Coupling and Reliability: Connecting Normal Accidents Theory and High Reliability Theory

In this article, the theoretical debate between two dominant schools on the origins of accidents and reliability, Normal Accident Theory and High Reliability Theory, is continued and evaluated. Normal Accident Theory holds that, no matter what organizations do, accidents are inevitable in complex, tightly–coupled systems. High Reliability Theory asserts that organizations can contribute significantly to the prevention of accidents. To break through this deadlock, the mutual effects of complexity and tight–coupling, on the one hand, and reliability–enhancing strategies, on the other, are examined. It becomes clear that the theories are sometimes in conflict but that sometimes they also reach similar conclusions when applied to case events or generic safety problems. Cross–fertilization is, therefore, possible.