1. A method for controlling a placement of an edge of an image of a reticle pattern formed on a wafer in a lithographic exposure process with an exposure tool having an optical projection system, the method comprising: determining first operational factors based on operation of said exposure tool, the first operational factors representing the exposure tool the first operational factors including i) setup parameters of said exposure tool; ii) optical aberrations of an illuminator and a projection lens of the optical projection system, the illuminator and the projection lens being in optical communication through a reticle carrying the reticle pattern; and iii) a signature of the optical system of the exposure tool; optimizing, with a computer device, a merit function to produce a value of a change of a setup parameter from the setup parameters, wherein the merit function represents a contribution of a first operational factor, from the first operational factors, to a first measure of a shift in a position of an edge of said image with respect to a target position thereof; and modifying, based on said value of the change, the exposure tool by changing at least one of a) one or more of a presence, position, orientation, size and shape of an optical component of the optical projection system; and b) a parameter of scanning synchronization of the exposure tool to form an image with a second measure of said shift, wherein the second measure is reduced in comparison with the first measure.