success vs attainment

success and attainment both are nouns.

Word	Noun	Adjective	Verb	Adverb
success	Yes	No	No	No
attainment	Yes	No	No	No

As nouns, attainment is a hypernym of success; that is, attainment is a word with a broader meaning than success:

success (noun)	attainment (noun)
an attainment that is successful	the act of achieving an aim
an event that accomplishes its intended purpose	arrival at a new stage
a person with a record of successes	an ability that has been acquired by training
a state of prosperity or fame