Event analysis and the problem of causality

The general dependence on large scale systems together with rapidly changing technology require predictive models of the performance of complex systems in order to be able to judge in advance the functionality and safety of new system concepts. Complex systems including human actors, however, cannot be modelled by quantitative, deterministic models and causal models in terms of objects and events have typically been adopted.The paper presents a discussion of several basic difficulties with this approach. Post-hoc identification of causes of an accident depends on a pragmatic stop-rule for the termination of the analysis. This has theoretical, as well as ethical and legal implications.Empirical verification of the design of a complex system, likewise, raises the question of stop-rules for adjusting the experimental conditions.