time-motion study vs scrutiny

time-motion study and scrutiny both are nouns.

Word	Noun	Adjective	Verb	Adverb
time-motion study	Yes	No	No	No
scrutiny	Yes	No	No	No

As nouns, scrutiny is a hypernym of time-motion study; that is, scrutiny is a word with a broader meaning than time-motion study:

time-motion study: an analysis of a specific job in an effort to find the most efficient method in terms of time and effort
scrutiny: the act of examining something closely (as for mistakes)

Other hypernyms of time-motion study include examination.

time-motion study (noun)	scrutiny (noun)
an analysis of a specific job in an effort to find the most efficient method in terms of time and effort	the act of examining something closely (as for mistakes)
	a prolonged intense look