Henry gantt, one of the operations management theorists _.
a. devised charts for operations scheduling, which refers to the determination of the quantity of jobs and sequence in which jobs and activities should be completed.
b. is regarded as the father of scientifi management, with the accent on the efficient use of time to improve productivity in the workplace
c. become interested in saving time, improving productivity and removing activities which are necessary for employees to perform.
d. emphased the specialisation of labour to improve the productivitof employees in the organization