In this paper, after applying Response Surface Methodology (RSM) for Robust Parameter Design, we take into account two equations representing the mean and variance responses. Then, the control factors are determined such that these two objective functions are close to their ideal values. In this regard, the Lp
method is used and its sensitivity analysis is accomplished through a numerical example for the larger- the better case. Moreover, in this study the impact of ignoring uncontrollable noise factors in estimation of the optimum points are investigated.