Evaluation includes developing a hypothesis regarding the cause of the plant problem. This stage can be improved with good problem solving training, such as the Kepner-Trego Problem Solving & Decision Making Methodology. Having the ability to test a hypothesis is recognized as a best practice. This means the operator has to first have time to respond and study the problem. Waiting for late alarms will not provide this. If either a system (state-estimator technology) or an operator (tracking trends and displays) facilitates early detection of an impending failure, operators should have a training room close by the control room that allows them to track the occurring event while testing theories on a real-time dynamic simulator.
Acting. The operations and technical support team must take corrective action, which may entail the use of the automation control system or the control operator verbally instructing a field operator to make adjustments to process equipment. But the possibility of an inappropriate action by the operations team can initiate or escalate disturbances. Here is where good training (based on competency models) and continuous practice of skill development ideally by simulators can make a big impact on success.
Assessing is another place where we encounter many failures as the operations team make a move, and instead of assessing and continuously monitoring the actions taken until a confirmed success and stable process, the operators leave the monitoring to the automation system and wait for the next wakeup call; e.g. another alarm. This is how operators miss the knock-on or domino effects of a failure and orient themselves late in the process event, getting themselves into the continuous fire-fighting mode of operating.
Training and Environment
Development of a mental model of the process has been recognized as a best practice. Current practice to achieve this requires console operators to be competent in each of the existing field operator positions achieved by learning and experiencing these jobs.
Development of staffing workload assessments against each console operator position and balancing workload based on experience and competence will allow a formal training system to deliver the performance required. However, continuous improvement and tracking of performance using quantitative measures obtained by observance and qualitative analysis of DCS data should be the role of supervision.
Operator training should be based on competency models and include the opportunity to practice skills on a regular basis, rehearsing critical response, practicing standard operating procedures and emergency response actions. The console operators function as process control specialists and effectively control, optimize and troubleshoot the process to meet production goals. They should be able to successfully manage abnormal situations directing outside operators in routine and abnormal responses. The control room and adjacent support rooms should create a continuous learning environment.
The workspace design is usually only addressed if a new control room is being proposed or built or significant change is occurring due to a technology upgrade or reduction in operations personnel. It is generally focused on the control room. They have evolved from equipment shelters to sophisticated computer rooms to control centers for people, with equipment and computers taking a second place.
Control room designs vary from the “functional design,” where console layout is the primary focus and communication and collaboration drive the layout, to “theater style,” where all consoles face a video wall and the off-workstations provide a panoramic view of the whole plant. Each console has its scope of control on one or two of these off-workstations, while the operator sits at the console able to see adjacent units and detailed information about units, sub-units, trends, procedures and alarms.
The control room should address operator vigilance and other performance-shaping issues and should be specified as part of the Console Operator Performance Standard. One of our customers has adopted a fatigue countermeasure program that involves education and workspace design issues such as circadian lighting, nap rooms, noise reduction, HVAC systems that have people-zoned areas, ergonomic furniture and software that addresses common human factor issues and stressors.
Although technology and a poor work environment can produce impressive profits, lack of concern for people and the environment and systems that supports them can blow away these and future profits for many years.
Ian Nimmo is President and founder of User Centered Design Services an ASM Consortium affiliate member and an ASM service provider. He is a member of the IEEE and a senior member of ISA.