In the former paper titled “Probabilistic Safety Assessment Method of Ship (Part 2 : A Risk Evaluation Methodology for FSA), a holistic methodology to evaluate risks of the ship in which several safety measures will be installed was introduced. As a possible problem of that methodology it was indicated that the number of disaster escalation scenarios would be increased so that to carry out disaster escalation and evacuation simulation may be impracticable. In this paper the developed method to resolve this problem and the trial application of this method are introduced. The characteristics of the method is to define probabilistic density function of success time at each event which affects disaster escalation directly. To do this event tree could be small, therefore the event sequences along which simulation should be carried out would be very few.