Railway transportation networks are complex systems of systems which exhibit emerging behaviors. Emergence is the property that distinguishes a collection of things from a system which provides a behavior not attainable by any subset of system constituents. At the railway network level, the necessity of proving the desired emerging behaviors, revealing undesired patterns of behavior, and providing evidence that the rate of occurrence of a particular undesired one is below a specific threshold is stated in the RAMS standard. This short paper briefly discusses different aspects of this approach and elaborates on a successful example.
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The article by Rasmussen (1997) begins with an introduction that risk management is treated differently across all relevant hierarchical levels of a socio-technical system. However, due to the dynamics of the system, treating risk-related decision-making in isolation does not enable us to recognize when we cross the boundary of safe operation. Thus, when assessing risks in a complex socio-technical system, we have to include the layers of legislation, management, work planners and system operators. As a result, we need to touch upon risk models of the disciplines varying from economics, organizational theories and cognitive psychology to engineering.
Continue reading “Review: Rasmussen’s 1997 paper – Risk management in a dynamic society: A modeling problem”