This project examined the impact of APC use, focusing specifically on whether its use degrades operator skills over time.
This project examined the impact of advanced process control (APC) on the skills of the operator, specifically investigation if there a reduction in effectiveness with prolonged APC use. The research was undertaken by Dr. James Henry of Lamar University examining the effects using both industry data and a student study. No conclusion could be discerned using the industrial data which was based on alarm and event data. The student study clearly identifies a relationship between time using APC and the reduced performance in managing the process without APC. The time to regain proficiency was also illustrated.
When Advanced Process Control (APC) is fully or partially turned off the operator has lost some of his/her skills to effectively operate the process.
A. Does an operator actually lose his/her feel for the process by continuously running on APC?
B. Are there effective ways to train an operator so that he/she does not lose that skill? (Phase II)?
Automation has changed the way operators perceive and run their plants. One hundred years ago, operators manually adjusted the operation of a plant by turning valves and, as such, an operator would learn the effect of turning a valve say ½ a turn. Every valve was essentially a degree of freedom for plant operation.
In the 1930’s with the invention of the pneumatic PID controller, the valve degree of freedom was replaced with a flow or pressure measurement changing how an operator understood his plant. With cascade control, the degree of freedom was moved once again from valve to flow to level or temperature. Finally, with advanced control the degree of freedom was moved to a stream composition or some calculated variable with a potential maximization or minimization algorithm attached.
If an operator’s interaction with the process is the Advanced Process Control (APC) variables only, the question becomes, has the operator’s understanding of the process changed so that he/she is unable to control the equipment without the APC? This situation can happen during an instrument failure or if operation goes outside the APC operating limits or if an instrument is taken out for maintenance. The APC can either be fully off or partially turned off.
1) Monthly and final reports, along with suggestions for future extensions will be provided.
2) Provide equation and algorithm for evaluating operator effectiveness based on findings of this study.