This paper reviews the theoretical bases of the barrier modelling analysis, and introduces a novel approach for considering the barrier effects on the probability of the events through the event tree analysis. A structure for modelling barrier sets is developed. Using the techniques of the reliability analysis, an approach for calculating the effects of the barriers on the probability of events is introduced. This model is used to develop a risk analysis workbench in an industrial design application system, which can be used to analyse the risk during industrial systems design phases
