Abstract: A spent anode is replaced with a new anode in an electrolysis cell having an anode bus bar and an anode rod contacting the bus bar. A desired distance (D4) from the bus bar to a reference point on or adjacent to an anode rod for the new anode is calculated, the spent anode is replaced with a new anode so that the reference point on the new anode rod is spaced from the bus bar by an actual distance (D5), and the actual distance (D5) is measured at least once by means of a vision system. The actual distance (D5) is preferably adjusted using a feedback control loop in a computer so that D5 approaches the desired distance (D4).