Originally Posted by air pig
Hitler's main problem was his strategic decision making in 1941, when he helped Mussolini and attacked Russia within months of each other.
IRRC, in Speer's biography he said something like "Planning was based on the war getting going in 1942/43". Hitler got so carried away by his early successes that he decided to just 'keep on going' regardless of the original plans and production issues. So he invaded the wastes of Russia with a horse-drawn Wehrmacht, with the consequences we now know.
Similarly, war material production continued in parallel with extensive domestic production, so that Gerta would never have a problem getting a new sewing machine or kettle.