Standardized Risk Models for Formal Safety Assessment of Maritime Transportation

Abstract

The overall purpose of maritime safety regulations is to establish minimum requirements in order to ensure that at least a prescribed level of safety can be maintained. The purpose of Formal Safety Assessment is to evaluate current safety regulations by estimating the average risk levels that may be associated with these minimum requirements, averaged over i.a. time, space and a population of ships, and possibly to recommend improved regulations. In this paper, a standardized structure for conceptual risk models of the most critical accident scenarios pertaining to shipping is proposed. Based on these risk models, detailed event tree models may be developed for particular shiptypes and applications in a straightforward and consistent manner. Such standardized risk models will also facilitate development and integration of software tools and other partial risk models as parts of the overall risk model. The standardized risk models developed in this paper include the risk to life (crew and passengers where applicable), as well as the risk of accidental pollution and financial accident cost related to loss of ship and cargo. There are several benefits from having standardized risk models for use in Formal Safety Assessments. Obviously, standardized risk models, if commonly accepted, will ease the workload of future Formal Safety Assessment applications in that new risk models will not need to be developed on a case by case basis. Improved consistency, comparability and transparency may be achieved which will also ease the evaluation and validation of risk analyses and recommendations from future Formal Safety Assessments.