Forge Worlds are the powerhouses of the Imperium’s military machine, but Manufactorums are not only located there. Well populated planets of C and H Class have their own industries or even tvehicle and weapon manufactorums to supply their planetary defence regiments and ‘tithed’ Astra Militarum forces. Hive Worlds double as huge factory complexes, employing millions and ruled by autocratic mechant cartels or representatives of the Hive’s ruling aristocracy.
Secondary Manufactorums lack specialised technical knowledge and instead replicate plans granted by the Adeptus Mechanicus for the most common patterns and designs. The Adeptus Mechanicus monitors closely these facilities.
Hive Worlds like Armageddon have their production tailored to their classificationa as Warzone, producing, for instance, Chimera armoured carriers directly allocated to the Armageddon Steel Legion regiments and PDF regiments. The surplus production is transported off-world to neighbouring Astra Militarum regiments fighting in nearby regiments, as per the dictations of the Munitorum.
The Departmento Munitorum provides fuel, food, water, weapons and ammunition for the Astra Militarum operating in a Warzone (or stationed in a backwater sentry post), in addition to the requirements for maintenance, repair and recovery of battle-damaged vehicles. For this purpose, the Deparmento Munitorum establishes Field Workshops with Adeptus Mechanicus attachments which supervise the authorised use of the equipments and provide techncial expertise. The functions of a Departmento Munitorum Field Workshop is to repair, mantain, fix simple mechanical probles or replace entire parts (and ship the parts back to the Manufactorums), even salvage and cannibalise destroyed vehicles.
The field operations can create hybrid vehicles and jury-rigged designs, for the interchangeability and compatibility of STC designs is large
The Adeptus Astartes have their own production and supply but for the largest vehicles and items, which come directly from the Adeptus Mechanicus. Space Marine vehicles, unlike the mass-production patters used by the Astra Militarum, contain more classified technology and complex internal systems, in line with their use as the foremost weapons of war in the Imperium.