"On the factory floor" is a common phrase used to describe the physical space where manufacturing is undertaken. However, there are several synonyms that can be used instead of this phrase to add variety to your writing. Some of these include "in the production line," "in the manufacturing plant," and "on the assembly line." Other synonyms you could use include "on the shop floor," "in the workshop," and "in the fabrication center." Each of these synonyms can be used interchangeably with "on the factory floor" to convey the same meaning and add a different tone to your writing. Furthermore, using synonyms helps you to avoid repetition and make your writing more interesting.