The frequent, and often conflicting, changes in operational requirements led to numerous changes in aircraft specification and designs so that manufacturers like Messerschmitt were unable to focus outright on a few aircraft types and, most importantly, production output. The Germans failed to put their production on a war footing, continued to run factories only eight hours a day, and failed to include women in the workforce. German World War II aircraft production output did not rise as steeply as Allied output, especially Soviet production, which exceeded Germany's in 1942 and 1943.