Process unit is a term used in the engineering and manufacturing industries to refer to a unit of production that is part of a larger process. It is typically composed of several components that work together to produce a desired outcome. The term STEP, which is a four-letter word, is often used to describe the process unit. It stands for Systematic, Technical, Engineering, and Production. This acronym describes the various components that make up the process unit, such as the system design, technical specifications, engineering processes, and production methods.