Operator training simulators can help meet plant-wide safety goals
Operator training simulators (OTSs) can be a major asset to a large plant or refinery. However, many managers consider them more as an expense, a sink for valuable resources, without looking at their utility in sustaining plant safety and reducing costly shutdowns. I think it’s time to shed some light on the value that these simulators can contribute to a process.
At steady-state, a healthy plant operates as a well-oiled machine. Its control system smoothly allows the process to be self-correcting when an upset or disturbance occurs. Some disruptions are significant enough that they require operators to take corrective action to restore the process to steady state. In rare cases, a disturbance upsets the plant so significantly that the only safe move for an operator to make is to shut down the plant as quickly and safely as possible. Of course, the safety instrumented system should take control over the critical process components, but there are many additional moves that must be made to shut down a process.
This is where OTS comes into play. Regular operator refresher training at an OTS is like changing the oil in your car—the skill set needed to respond to emergencies and process disturbances are reset and refreshed, giving the operator what they need to continue regular operations. (I know, I know—the old “oil change analogy.” But it really is quite versatile.)
At many major refineries, operators are required to log a specified number of hours at an OTS, under the supervision of a certified area trainer. The trainer is typically a seasoned veteran who has personally experienced some of the worst-case scenarios and can pass along the knowledge needed to guide the process to its de-energized state. He or she can instill in the “green” operator the necessary fear and respect for the process they’re controlling. After many rounds of practicing the hypothetical scenarios on the OTS, the new operator learns and grows comfortable using the steps required to maintain process safety through all the various types of upsets that could occur.
Let’s look at some things to consider when choosing an OTS. By carefully considering these factors, you can avoid ballooning maintenance costs and ensure round-the-clock availability for all different types of training.
What types of training will your operators require?
Will your OTS be used to “break in” new operators or do you plan on them learning in real time, on the running process? Do your start-ups and shut-downs involve critical, life-safety steps that need extensive practice and instruction? What types of refresher training will your require? Once you’ve identified the types of training your operators require and the degree to which your OTS will be utilized, you can decide the extent to which your model needs to be maintained.
Maintaining model fidelity
The best OTS makes use of the most up-to-date model that, ideally, is an exact replica of the distributed control system (DCS) running in the plant. But even the best-designed plant continues to evolve and change; equipment and instrumentation reaches its end of life and is replaced; expansions are built to increase capacity and thus equipment is sized-up; and the relevant control loops must be re-tuned each time a change is made. The process is constantly changing and the model must change along with it to keep up. If the model isn’t maintained at regular intervals, it doesn’t take long before fidelity drops to a point that it becomes unusable. And it’s cheaper to update a model several times a year, than to create a new one every five to 10 years.
Don’t ignore the total cost of ownership
Model maintenance will be the biggest expense once you take possession of the OTS and the first version of the model. It’s important to view your OTS as an investment, albeit one with an intangible return. Mandating refresher training and emergency preparedness for operators at regular intervals using well maintained high fidelity models will reduce loss of containment events, increase operator safety, and minimize the number of shutdowns over time. Just as getting regularly scheduled oil changes in your car will ensure that it continues to run efficiently for many years. So be sure to budget for model maintenance and plan on maintaining your OTS for the entire life cycle of your DCS.
With an up to date model, your operators receive the continuous training necessary for plant operations. Your sterling safety record continues unblemished because your operators have the confidence they need to react correctly in those rare emergency upsets to the plant. After all, you don’t want them seizing up like a neglected car engine the next time your plant is hit with a critical upset.
This post was written by Matthew Thibodaux. Matthew is an Engineer II at MAVERICK Technologies, a leading automation solutions provider offering industrial automation, strategic manufacturing, and enterprise integration services for the process industries. MAVERICK delivers expertise and consulting in a wide variety of areas including industrial automation controls, distributed control systems, manufacturing execution systems, operational strategy, business process optimization and more.