A method of controlling a track apparatus in a lithocell apparatus arrangement, is presented herein. The lithocell includes a lithographic exposure apparatus configured to expose substrates and a track apparatus configured to prepare substrates before exposure and develop substrates after exposure. The method includes predicting times at which the lithographic exposure apparatus will be available to accept a prepared substrate for exposure from the track apparatus, and adjusting a rate at which the track apparatus prepares substrates so that a substrate is prepared in time for acceptance by the lithographic exposure apparatus.