A method for performing optical proximity correction with process variations considerations is disclosed. The maximum aerial gradient direction for a control point associated with an edge is initially determined. Then, a variational edge placement error E along the maximum aerial image intensity gradient direction of the control point is calculated. A determination is made whether or not |CE·n| is equal to or greater than a manufacturing grid, where n is the direction perpendicular to a segment pointing outward, and C is a constant. If |CE·n| is equal to or greater than a manufacturing grid, the edge is moved by −CE·n.