Although Aluminium is the least cost solution as presented in Figure 38, it suffers from higher installation costs. The welding process is difficult, expensive, and requires highly trained labor. Aluminium also has a lower tensile strength than steel and therefore requires stronger structure to support the hull, equipment, and armament. This results in more structure and thus higher costs. The PODAC system has the capability with CER's to incorporate the build complexity production into its predictions. its and comprehensive difficulty of production into its predictions.