This paper addresses the issue of improving the efficiency and effectiveness of ship design, particularly at the concept stage. Firstly, current developments in design theory and ship design methods such as systems engineering, decision support systems and multicriterial methods are reviewed, specifically with respect to ship design synthesis. To improve ship design, it is mandatory to change strategy moving from sequential spiral approach towards advanced methodologies that facilitate decision exploration. New strategies should be intended to substantially reduce the computational intensity of ship design and to place the design process into a more flexible and natural framework. For purpose of concept ship design, a very comprehensive design methodology, e.g. a multiattribute decision-making approach (MADM) is dealt with, which appears to enhance design creativity and effectiveness. The approach is based on fuzzy-set to capture the features of imprecise and vague information that are usually present at concept design phase. Robustness concept is introduced to show how variations of uncertain parameters handled by orthogonal array method influence the selection of the so-called optimal ship from the viewpoint of overall lifetime cost. Advantages of providing rational ship synthesis are outlined. Finally, the details of the approach are illustrated with a concept design example of fast cruiser vessels.
