This paper was first presented at the NAV99/ILA28 Conference on ‘Loran-C, Satellite and Integrated Systems for the 21st Century’ held at Church House, Westminster, London from 1–3 November 1999.

The introduction of modern navigation systems highlights the need for efficient tools to assess the possible impact of these systems on the safety levels currently associated with the operation of a ship. In recent years this has led to investigation of the advanced safety/risk assessment techniques already applied in other industrial sectors, with encouraging results. The scope of this paper is to show a quantified safety assessment methodology that can be applied while designing or retrofitting navigation systems. The methodology adopted is the result of the review of the IMO Formal Safety Assessment (FSA) technique and comprises the development of a functional analysis, a hazard identification analysis and a risk assessment. The paper provides details on a specific application of this model to an integrated navigation system. This application is included in the work performed under the ATOMOS II research project, partly funded by the DGVII Directorate of the European Commission within the 4th Framework Programme in the field of Maritime Transport.