This study presents an effective methodology for the optimum design of two-component armor. The armor consists of two plates: one is boron carbide ceramic and the other is kevlar/epoxy composites. The effect of the thickness of two plates on the ballistic limit velocities of the armor was investigated by Florence model. A finite element model was created using MSC.DYTRAN to simulate the impact of a rigid projectile on the composite armor. The optimum thickness of the ceramic and composite was obtained by evaluating the ballistic resistance efficiency.