97 International Journal of Materials &Structural Reliability International Journal of Material & Structural Reliability Vol. 6, No. 1, March 2008; 97-107 Applying Performability Modelling in Maritime Risk Assessment E. Mennis 1*, A. Platis 2 and N. Nikitakos 1 1 Department of Shipping, Trade and Transport, University of the Aegean, Korai 2a 82100, Chios, Greece 2 Department of Financial and Management Engineering, University of the Aegean, Korai 2a 82100, Chios, Greece Abstract In the last decades Formal Safety Assessment is a methodology used for the estimation of maritime risk with the ambition to provide improved regulation for the improvement of safety at sea. Several studies have been shown that a great number of techniques can be efficiently applied at the field of maritime risk, such as Event Trees, Fault Trees or FMECA contributing mainly at the first two phases of FSA. This study analyzes the previous techniques and examines the case of applying homogeneous continuous time Markov chains at supporting the cost – benefit assessment phase, which is the fifth step of FSA. At the end a numerical example is given in the case of a containership company, to illustrate that useful information can be provided at the field of decision making in the maritime industry. Keywords: Maritime, Risk Assessment, Formal Safety Assessment, Markov Models, Maintenance 1. Introduction Most of the studies conducted in the FSA approach concern risk assessment through a series of techniques such as FMECA, Fault trees, Event Trees etc. In this paper is given an analysis of these methods which are used in step one and two of Formal Safety Assessment. It will be shown how Markov modelling could contribute in step five of the FSA procedure, by computing and comparing different cost solutions for better performability of the ships in maritime industry. Section two includes a presentation of the methodologies and a comparison between static modelling and dynamic modelling. Section three illustrates a model of two ships management in the area of containers. Section four gives a numerical example of the model. 1* Corresponding author Email: v.mennis@aegean.gr