https://en.m.wikipedia.org/wiki/New_Economic_PolicyNEP economic reforms aimed to take a step back from central planning and allow the economy to become more independent. NEP labor reforms tied labor to productivity, incentivizing the reduction of costs and the redoubled efforts of labor. Labor unions became independent civic organizations.[citation needed] NEP reforms also opened up government positions to the most qualified workers. The NEP gave opportunities for the government to use engineers, specialists, and intelligentsia for cost accounting, equipment purchasing, efficiency procedures, railway construction, and industrial administration. A new class of "NEPmen" thrived. These private traders opened up urban firms hiring up to 20 workers. NEPmen also included rural artisan craftsmen selling their wares on the private market.
It seems to me that at least from the start, Lenin's NEP had shown some promise as a viable economic policy for the Soviet Union.
Possibly one better than Stalin's centrally planned command economy of the later years.
That being said, if the NEP had lasted past OTL's kill date, could it have realistically worked long term?