Process Controls: What is It Exactly?

 “Do you really want to work in process controls, or are you just trying to get a surface-level feel for the job?”

The question above had been privately asked by various people during the first few years that I worked in the oil & gas industry. Granted, it was and still is a legitimate question for any individual. Although the enthusiasm and new perspectives of engineering college graduates can be a breath of fresh air in most companies, there can also be a sense of wariness from more experienced employees who are cautious about training people that are merely dabbling in the work with no intention of staying beyond one year in the field.

Personally, I am a proponent of those who are unafraid to dabble and try what is outside of their comfort zone. Sometimes the most unexpected yet wonderful outcomes are the direct result of just “trying something out”!

Although job titles such as “process controls engineer”, “controls engineer”, “control systems engineer”, etc all seem to have little variation to them, there are discrepancies that segregate different fractions of work within the generic “process controls” term.

This article will attempt to cover one major difference in order to help any readers who are curious about this line of work or who are on the cusp of dabbling in this field. Please note that this is just one person’s experience in the oil & gas industry, and that the arena of process controls can vary depending on the type of industry that is being discussed (pharmaceutical, food and drinks, etc).

In the oil & gas industry, people utilize computers and automated systems to help monitor and operate running facilities such as refineries and petrochemical plants. Yes, people still walk around to visually look at operating equipment within the facilities, and they can use a significant amount of muscle strength to turn valves and lift heavy loads. However, most competitive facilities also utilize the advantages of modern technology to run and optimize their plants from within a centralized building.

The generic term “process controls” is usually given to the department of people who directly work on the automated systems that run and optimize the plants. These automated systems can include anything from computer keyboards/microphones/monitor setups to the Windows OS-based computers that run specialized process controls software (some industry staples would be Honeywell Experion PKS or Siemens PCS7) to the physical hardware (field termination wiring, input/output cards, communication modules, etc) that allows the process controls software to be able to detect and control how physical instrumentation valves in the field should be moving.  A jack-of-all-trades could attempt to work on everything in the job field description, but that’s not necessarily the best way to utilize human resources (especially in large corporations).

The individuals who work on maintaining the health of the process controls systems are generally referred to as “control systems engineers” or “systems engineers”, even though they may be in the generic department labeled as process controls. These people ensure that servers, computer console stations, and process control hardware (communication modules, processors, input/output cards, etc) are fully functional at all times. Even system network interactions can fall into this category, though there can be a separate system network department that works on maintaining items such as firewalls and routers.

When process control system improvements are released by their respective vendors in the form of software patches or system upgrades, the control system engineers have to be very careful in their roadmap on how to execute the upgrades (especially since they want to minimize disruptions to running facilities). Currently, many companies are trying to figure out how to maintain and/or replace obsolescent process controls systems from the 1970s and 1980s, so job opportunities in this field are plentiful. I have found that people of varying engineering and other technical backgrounds can have control systems jobs, but most of the lead control system engineers that I have worked with actually have electrical engineering backgrounds.

In contrast, “process control engineers” are generally those who concentrate on improving the physical process of making product by utilizing the tools provided by the process control systems. For example, if there was a need to balance the amount of feed gas A going into a reactor with the amount of feed gas B going into the same reactor, then the process control engineer would implement a control strategy on the process control system to automate the ratio balance of the two feed gases.

A control strategy can be likened to specialized computer code that is created by using a library of specialized computer blocks to make a desired action or calculation occur within the process control system. Although the process control engineer would need to understand the nuances and limitations of the process control system, he/she would be expected to place more focus on understanding the chemical processes of the plants and applying automated control strategies to help make more product (aka generate more money) or reduce utility usage (aka help save more money by spending less on raw materials).

In my experience, process control engineers generally have a strong background in chemical engineering and are sometimes considered to be process engineers who are especially “computer savvy”!

Evidently, there is a sizeable difference between working on the “systems side” of process controls and working on the “process side” of process controls. If there are any readers who feel as if they may want to try their hands in this field, I would suggest that they think about which aspect of process controls is more interesting to them. One analogy I like to think about is whether someone prefers learning about the tool itself (systems side) or if someone prefers learning about how to apply the tool (process side).

Either way, there is no wrong choice – modern technology and automation are here to stay, and prospects within process controls will only grow and change as long as the voracious consumer demand for products continue to increase.

Joyce Ho
About the Author

Joyce Ho is a driven engineer, mentor, and leader who graduated from UCLA with a B.S. in Chemical Engineering. She has held a wide variety of roles within the process controls field for the oil and gas industries, which span working on both DMC/MPC applications as well as DCS/PLC platforms. She has worked for such Fortune 500 companies as Phillips 66 and Air Products, and she is in the process of obtaining her PE license. 


Her passions include advancing more engineers in their careers and becoming an expert in the field of process controls. The two most motivating people in her life are her parents, who were both immigrants from China and came to the United States with scarce amounts of money and very little formal education. Like most second generation Americans, Joyce straddled two different worlds while growing up in Southern California (the “world” inside of the home and the “other world” outside of the home), an experience which has greatly influenced her perspectives on career ambitions and personal life goal.


Joyce is an active, long-term mentor to several engineers with a wealth of knowledge on interviewing, resume writing, networking, and more. Joyce is passionate to help develop more women in engineering through her wealth of experience and active mentorship. In “Process Controls: What is it Exactly?” she makes a strong and detailed case to pursue a career in process controls. We are excited to share her experiences in process controls. Read more to find out more.