Risk management in total system ship design

Ships are being designed with an increased emphasis on reduced lifecycle costs, obtained through means such as reduced crew size, increased automation, and adoption of commercial practices. Ship cost is closely related to the likelihood and consequence of future events, or risk. Ship designers must have tools to assess and manage risks to obtain cost-effective designs. Risk assumptions were built into prescriptive standards, but performance standards are now being used. Ships systems built to varying degrees of acceptable risk are not cost-effective. Under-designs and over-designs will result, and the ship ends up only as strong as its weakest link. The authors propose that a Top-Down Risk Management methodology that is currently used for commercial ships be considered for use by naval ship designers in conjunction with both the traditional ship design spiral and the Total Systems Ship Design concept. The IMO-endorsed Formal Safety Assessment (FSA) methodology was designed for marine systems. By adopting the FSA approach the Navy will benefit from existing lessons-learned, and will have a smoother transition into the application of commercial standards when the ship is built.