Total System Ship Design in a Supersystem Framework

ABSTRACT Naval architects are skilled at turning a set of ship performance requirements into the engineering description of a ship capable of meeting them. That is the technical side of the problem, and our ability to deal with it has steadily improved. But the ship design problem has other major aspects that must be dealt with just as competently if the ultimate result is to be the best, most cost‐effective ship possible. This paper proposes some major changes in the way naval ship design is approached. It provides a high level description of the entire process of early stage ship design and in doing so expands considerably on the traditional boundaries of that process. It places that process in its larger context of mission requirements determination, operational effectiveness assessment, and program management review and control, all of which influence a ship's technical characteristics and capabilities. It outlines the various elements of analysis, design, estimating and assessment involved and shows how they are interrelated and must be worked interactively in a comprehensive and systematic process if an optimal ship design is to be achieved. Interwoven with this expanded design process is an expanded context for understanding the role of the ship being designed. This paper introduces the idea of a “supersystem” containing all the other operational systems, facilities and support infrastructure the new ship system will have to operate jointly and compatibly with. It explains why total‐system design and optimization must be focused at the supersystem level and not merely at the level of the new ship itself. Since this expanded focus requires looking for factors and effects in areas that have not generally been thought relevant, some principles and guidelines for recognizing them are provided. The paper clarifies the issue of “measures of effectiveness” (MOEs) versus “measures of performance” (MOPs) and shows how each should be determined and used. It shows how high level MOEs and the design philosophy can be distilled from the mission requirements even before any technical design work has begun. The practical use of modeling and simulation in matching the MOPs of an alternative system concept against the MOEs required by the mission is discussed.