Ordnance functioned as a component within the Imperial Navy's Support Service Branch, and its core function centered around the setup and upkeep of the Imperial Navy's diverse array of weaponry.
Within the initial 1989 printing of the Imperial Sourcebook, also known as the first edition, Ordnance was identified as the Support Service Branch division that was in charge of armament utilization. However, the entry was revised in the second edition, which was published in 1994; the revised entry stated that Ordnance's role was to install and maintain the weapons, while the newly formed Gunnery division took over the operation of those weapons.