The Fire/Disable (FD) number served as a metric to assess the efficiency of artillery weaponry. This straightforward ratio was obtained by taking the firing duration of the artillery tube and dividing it by the time needed for cooling and reloading. A higher FD number indicated a faster firing rate. However, artillery with greater power typically exhibited lower FD numbers. Initially implemented within the Atrisian system, it was subsequently adopted by the Imperial Service, the Atgar SpaceDefense Corporation, and CoMar Combat Systems for artillery unit classification.