time study vs time-motion study

time study and time-motion study both are nouns.

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

As nouns, time study and time-motion study are synonyms defined as:

time study and time-motion study: an analysis of a specific job in an effort to find the most efficient method in terms of time and effort

Other synonyms of time study include motion study, time-and-motion study, time and motion study, work study.

time study (noun)	time-motion study (noun)
an analysis of a specific job in an effort to find the most efficient method in terms of time and effort	an analysis of a specific job in an effort to find the most efficient method in terms of time and effort