If you define "the communists" as "the Chinese communist party", then judging from China's development they've done a fine job. This was not quite true during the 1950's, when the head of the communists was Mao.
It's also questionable to define the economic system of Deng's China as "communist" in the same way as Soviet Russia and, say, Cuba.
It's also questionable to define the economic system of Deng's China as "communist" in the same way as Soviet Russia and, say, Cuba.