Soviet Union was so badly outmatched by Germany in all aspects of the industry it wasn't even funny. There was also a long gap after moving plants and workers to the East where the SU had de facto no industry left.
This is completely wrong.
The SU had more men, more tanks, more planes and more artillery when Barbarossa started.
We are talking about ratios for all these weapons of 3-4:1 in favor of the SU side.
The Germans started their attack on the SU with ~4000 tanks and ~700,000 ........ horses.
For the entirety of the war the SU produced more planes, more tanks and more artillery than Germany.
In tanks alone for every german tank the SU produced ~2.5.
The T-34 alone was build more often than all german tanks combined.
The SU produced as many tanks as the US.
There are many reasons for this:
- a far bigger population
- access to far more resources
- land-lease from the US
- saving factories from the germans and rebuilding them deep in russian territory
- "optimizing" their equipment on the expected time-span (if a tank on average only "lives" 1 month, it doesn't need high quality components that lasts years)
- the german industry being an unoptimized mess in the first years (to many factories and weapon types, endless battle between them for resources)
- the german industry not based on mass production, but compromised of high skilled workers
- the germans building their equipment in complete opposite of the SU style
- the german industry controlled by the army, often requesting changes that delayed completion of units