A design method has been developed to determine systematically the system variables that will best achieve multiple design objectives involving both cost and damage tolerance of horizontal vessel design. The method is computer based, and is particularly suited for designing pressure vessels using multiple (conflicting) objectives. The method has been tested and validated against a computer program used extensively in industry. Better results by the new design method are demonstrated through case studies. The results indicate a wide range of vessel dimensions to which the design method can be applied. In general, application of the method will increase the efficiency of the design of horizontal pressure vessels.