How Good Is Your Operator's Mental Model?
By Martin Berutti on 12.14.09
Mimic Simulation

In the December 2009 issue of Chemical Processing, David Strohbar of Beville Engineering and Danyele Harris-Thompson of Klein Associates, outline steps for preparing plant operators in their article, Build Operator Training Expertise Faster. Their article is based upon published findings from the Center for Operator Performance at Wright State University. The article is a concise and readable summary with practice lists of DO’s and DON’Ts for preparing inexperienced plant operators.

I had the opportunity to sit in on a presentation given by Dr. Jennie Gallimore of Wright State University at Emerson Exchange2009. In her presentation, Dr. Gallimore, used the term, mental model, to refer to an operator’s understanding of the complexity of a system and responses to external and internal factors. She stated that the more sophisticated the operator’s mental model of the process and control system, the more effective they would be in operating both safely and effectively. In the Chemical Processing article, Strohbar and Harris-Thompson state further: “Traditionally, operators have built expertise on a particular unit by experiencing numerous events. Such encounters result in a very accurate mental model for predicting what will occur in a situation and what actions will be needed to ensure safe operation.“.

The message of both the article and paper is that your operator’s effectiveness is only as good as their mental model of the plant and control system. Training activities and skill development should be focused on tasks that help your operator develop a mental model sophisticated, accurate enough to safely and effectively manage a complex process plant. .

Time Is Not On Our Side

Recent studies have made claims that it takes 7 years for an inexperienced operator to obtain the skills necessary for good risk-based decisions. With the average age of plant operators over 50 and 50% of the experienced plant operators retiring in the next 5 years, the process industries is running out of time. So how can the process user accelerate his inexperienced plant operators learning process, enabling the development of a sufficient mental model to operate the plant? Strohbar and Harris-Thompson give several suggestions. .

The Value of Practice

The authors make the claim that developing expertise is not done by acquiring knowledge. They state, “Novices also must engage in deliberate practice applying that knowledge, recognizing key information, setting goals and executing actions.” They continue “Expert mental models come from doing not reading.” .

The concept of deliberate practice has been a hot topic since Geoff Colvin of Fortune Magazine, used the term in his best selling book, Talent is Overrated. Deliberate practice for a process operator requires the use of a Virtual Plant / Control System dynamic simulator. The scenarios, repetition, cause and effect study required for true deliberate practice is too dangerous and expensive to perform on a running process. The off-line control system with a dynamic process simulator, responding closely to the real process, is a cost-effective tool that allows this accelerated learning process to occur. .

The Problems with OJT

Most process plants will tell you that most operators training is done On The Job (OJT) with an inexperienced operator following an experienced one. Strohbas and Harris-Thompson give several examples of things that should not be done for OJT activities and ideas of constructive activity. The big problem with OJT is the inconsistency in instruction and the lack of facility for the inexperienced operator to practice, make mistakes, and learn the cause and effect relationships. Although, it will be always be a part of an operator training program, a forward-thinking plant will focus their efforts on the use of the Virtual Plant / Control System for true knowledge transfer. .

Automation Helps and Hurts

While most chemical and hydrocarbon processes cannot be run without sophisticated process automation, Strohbas and Harris-Thompson state that it can “…diminish expertise…” The sophisticated mental model the plant operator needs to develop to effectively operate the process must include the control system. The Virtual Plant / Control System is only effective if the control system is an exact replica of the actual control system installed in the plant. The use of virtual control system simulators, like Emerson Process Management’s DeltaV Simulate are essential to meet this goal. Deliberate practice on the control system simulator (with the dynamic process simulator) allows the operator to understand the role and impact of control system actions without effecting plant production. .

The Virtual Plant / Control System consisting of a control system simulator and a dynamic process simulator should be considered by every plant operations manager. It is an effective tool available for allowing the plant operations staff to develop a sophisticated mental model of the control system and process without impact to the operations or safety of the plant. How good is your operator’s mental model of the plant and control system? Applying the principles found in the article, Build Operator Training Expertise Faster, with a Virtual Plant / Control System can change that model from simple to sophisticated.

Other Resources to Review

ARC Position Paper - Using Simulation to Optimize Results of Automation Projects
Operator Shortage Crisis and the Use of Dynamic Process Simulation
The Promise of the Virtual Plant

I look forward to your comments, questions, or suggestions.
Hope to hear from you soon.

Mart Berutti, 12/14/09