Which technique of Scientific Management violates Unity of Command?

Functional Foremenship

There is a technique associated with Scientific Management that can potentially violate the Unity of Command principle, and that is called "Functional Foremanship." Functional Foremanship involves dividing the responsibilities of a traditional supervisor into two categories:
(1) the planning function and (2) the execution function.
Under the factory manager there was a planning incharge and a production incharge. Under planning incharge four personnel namely instruction card clerk, route clerk, time and cost clerk and a disciplinarian worked. These four personnel would draft instructions for the workers, specify the route of production, prepare time and cost sheet and ensure discipline respectively. Under Production incharge, personnel who would work were speed boss, gang boss, repair boss, and inspector. These respectively were responsible for timely and accurate completion of job, keeping machines and tools etc., ready for operation by workers, ensure proper working condition of machines and tools and check the quality of work.