A prototype concurrent design optimization tool, named CELS for Concurrent Engineering of Layered Structures, has been developed. This tool can be used to analyze and/or optimize the conceptual design of a composite panel for Naval ship topside structures. CELS integrates five technology modules: (1) electromagnetic interference, (2) radar cross section, (3) structures, (4) cost, and (5) weight. Two optimization methods drive the integration of the technology modules. These methods include: (i) a local optimizer based on feasible sequential quadratic programming, and (ii) a global optimizer based on an exhaustive search. To obtain an objectively balanced design, "goodness" measures are allocated for each objective or constraint function. These measures, via a graphical user interface, allow topside designers to easily and quickly assess the impact of their decisions on various technologies. The utility and capability of CELS are demonstrated via the design of a topside composite panel. The design study shows that CELS can be easily adapted to different topside conceptual design problems, and that design tradeoffs can be performed quickly and used in decision making.