noun. The branch of engineering that is concerned with industrial processes, especially continuous ones such as the production of petrochemicals. Example sentences. 1  The smaller design and engineering company will handle process engineering, prototyping, testing, and production for Volvo's next-generation convertible. Nelson wants a career in process engineering and is pursuing a diploma in chemical engineering technology. 2  Investing in improved systems and processes-everything from product and process engineering to changes on the plant floor-also will help improve the quality of an operation and the vehicles it produces.