Abstract: A method and system are provided for use in positioning an article, from a group of similar articles, with respect to a processing tool to be applied to the article while the article is located on a stage. A first one of the articles is located on the stage at a predetermined registration of the first article with the stage corresponding to a certain angular orientation of the first article relative to the processing tool. An image of at least a part of the first article is acquired to determine, by image processing, the relative position of at least one site of interest on the first article with respect to the processing tool, thereby enabling to bring said at least one site of interest to the processing position. Data indicative of the relative position of said at least one site of interest of the first article is stored.