Purges of Gosplan confused administration in the 3rd Five Year Plan.
Removal of Kirov's supporters from the Politburo enabled Stalin to change the 2nd 5YP away from consumer goods.
Manager lied about production figures.
Removal of local industry managers was inefficient eg coal production stagnated in teh Donbad region of the Ukraine, where during the 5YPs it had trebled.
Moscow show trials removed Stalin's opponents.
Removal of Kirov's supporters eliminated moderates from the party.
Criticisms deflected onto 'wreckers…