<div class="htmlview paragraph">This paper presents an application of statistical methods to optimize product design. The study was to determine the appropriate dimension of rod diameter to effectively maintain the grip condition on the sunshade support rod and meet the sunshade effort requirement. Two statistical methods of experimental design and regression analysis were employed to determine the relationship between pull down force and rod diameter for different types of sunshades, to evaluate sunshade effort. The capability studies on sunshade effort for the recommended rod diameter have shown that pull down force meets the required specification for the three types of sunshades investigated.</div>