How did Soviet factories continue producing weapons after the German invasion?

Following the German invasion during Operation Barbarossa, the Soviet Union maintained its industrial capacity through a massive, organized relocation effort. As Soviet forces retreated, they implemented a scorched-earth policy to deny resources to the advancing German army.1

A critical component of this strategy was the systematic dismantling of entire steel and munitions plants located in the western regions of the U.S.S.R. These facilities were loaded onto trains and transported deep into the eastern territories, where they were reassembled and returned to production. This logistical feat allowed the Soviet Union to preserve its manufacturing base and continue producing the weaponry necessary to sustain the war effort despite the loss of territory.1