Confidence Building of a System Dynamics Model on the Causation of Construction Workers' Unsafe Behaviors

Abstract

To gain deep insight into the underlying causation and identify correspondent management strategies in the prevention of construction workers' unsafe behaviors, a conceptual system dynamics model was proposed. This paper mainly focuses on the confidence building of the model through model testing, which basically contains tests of model structure, model behavior, and model's policy implication. First, the conceptual model is quantified before the formal process of model tests. Second, the paper applies semistructured interviews for the structure-verification test to ensure the model's appropriateness in depicting the structure of the actual system. Third, tests of model behavior, such as extreme-condition tests and behavior-reproduction tests, are conducted so as to demonstrate the plausibility of the patterns and behaviors the model generates. Fourth, the model's policy implication tests are presented to examine whether the model's responses to predesigned policies are consistent with the actual system. As a result, the model shows confidence in revealing the underlying causation of unsafe behaviors, which can be used as reference to the routine safety management in practice. Further suggestions for the application of the model as a tool of simulation in real construction projects also are given.