Frank B. Gilbreth, Lillian M Gilbreth
Frank B Gilbreth and Lillian M Gilbreth begun to design motion study by using cameras to look at how body motions were used in the process of completing a job. This helped them to improve the processes and rearrange setups. That was known as motion study. Concept is to have smooth and easy motion to improve capability of performer and get more out of time investment done by that particular resource towards their given tasks.
Frederick W. Taylor
Frederick W Taylor started to design time study by stop watch and 2 clock method, Time studies were once used to establish performance-based wage rates and their capability.
Both study get merged and known as " Time and Motion Study " after decade.