An evaluation of the safety barrier system currently in place in the modern workplace is required to prevent major accidents and present new recommendations regarding safety levels. Safety barriers were classified and their components were described to evaluate their performance. We established a new evaluating method that included three indicators, namely the degree of confidence, the effectiveness and the economic impact. A calculation method is developed to assess each indicator using fuzzy mathematic theory. We described the progression of an accident considering the failure of safety barriers and used the observations to devise proper barriers to stop the propagation of unexpected events. The proposed method is applied to simulate a catastrophe involving the explosion of an oil storage facility which constitutes our case study. The obtained results are practical and applicable and show a high degree of quality and flexibility. (C) 2016 Elsevier Ltd. All rights reserved.