What is collectivism, in terms of grammar, of collectivisation?
Put another way:
Collectivism is the [which word?] of collectivisation?
Another example word pair might be centralism and centralisation.
I don't think there's a word describing either the relation of collectivism to collectivisation, or the reverse (the relation of collectivisation to collectivism).
They're both just alternative nominalizations — "a type of word formation in which a verb or an adjective (or other part of speech) is used as (or transformed into) a noun".
Noting this definition — "collectivization: the organization of a nation or economy on the basis of collectivism"— and the fact that "collectivism" gained currency first, I suppose one could argue that collectivization is a derivation (or derivative) of collectivism, rather than the other way around.