ABSTRACT
Interactive complexity refers to component interactions that are non-linear, unfamiliar, unexpected or unplanned, and either not visible or not immediately comprehensible for people running the system. The close proximity of parts that have no functional relationship, packed inside a compact airliner fuselage, can create the kind of interactive complexity and tight coupling that makes it hard to understand and control a propagating failure. A system with high interactive complexity can only be effectively controlled by a decentralized organization. In response to the limitations of event chain models and their derivatives, such as the latent failure model, models based on control theory have been proposed for accident analysis instead. Accident models based on control theory explicitly look at accidents as emerging from interactions among system components. Fighting violations or other deviations from presumed ways of operating safely – as implicitly encouraged by other models – is not very useful according to control theory.
