In the automation world today, we see a heavy emphasis on using operational data to drive strategic decision-making within an organization. There is certainly a lot of value in this, and the ability to make near real-time data available to decision-makers can offer a significant competitive advantage. However, we must be careful to not overlook the importance of operational personnel having the information they need to make tactical decisions—decisions that have an immediate and significant impact on safety, throughput and quality.
This information, which I like to call Big Process Data (BPD), is targeted at operators, often presented to them through their human-machine interface (HMI). It is imperative to carefully ensure that the definition of an HMI considers not just the process control system (PCS) screen, but any system that can provide information to the operator, such as a hardwired alarm panel, pneumatic control board, historian, lab information system or video camera.
Sounds obvious, right? Unfortunately, experience suggests otherwise. Before we begin to look at information presentation, it is essential that the fundamental elements of the system are working as designed. Properly functioning instrumentation is essential—it should be specified correctly, installed correctly, and maintained and calibrated periodically. How often do operators simply tolerate instruments that are not working or known to be inaccurate? This is often identified by the number of PCS overrides in place, alarms inhibited or controllers operating in manual. How many companies capture this sort of information as monthly KPIs?
Once we have a solid foundation, we can start to concentrate on providing the operators the information they need. The basis of a good HMI design is a thorough understanding of how the plant will work and how the operator interacts within. This can be accomplished by using one of the many formal task analysis methodologies to capture important information. I find that using a physical model, such as that in ISA-88, in the early stages of the design can offer big dividends. Performing this ground work will facilitate a task-based HMI design and coherent alarm configuration.
Hopefully, at this point, the operators have strong real-time data. We can further help them not only by putting data in a physical and operational context, but by providing tools to put the data in a temporal context. This is where historians play a big part: By allowing operators to view past performance, we can provide them a way to predict future performance and proactively address potential issues.
We refer to an operator’s situational awareness as the ability to detect, diagnose and respond to abnormal situations, and attempt to move them from a reactive to a proactive operational stance. Often, we have a very narrow view of what this means; therefore, it is important we do not lose sight of other sources of BPD. These need to be tightly integrated within the HMI to be of real value, for example:
• Video—real-time view of equipment or location (to detect leaks or mechanical breakdowns).
• Laboratory information systems—near real-time quality information on which to base process adjustments.
• Communications—not only radio to the field, but between operators as handover logs to maintain situation awareness across shifts.
• Building automation systems—often processes are susceptible to changes in temperature or humidity within the building.
• Weather information—outside equipment, such as distillation columns, can be impacted by rain events.
• Geo-positioning—real-time tracking of resource locations (such as load trucks in a mine).
Finally, we must remember to be cognizant of human limitations—even with the best-quality information, an operator who is overloaded or fatigued is not set up for success.
None of the above should come as a surprise. My message is that as we look to spend capital dollars, it is wise to make an honest determination of where it will have the greatest short- and long-term impact.
David Lee is a department manager at Avid Solutions Inc., a certified member of the Control System Integrators Association (CSIA). For more information about Avid Solutions, visit its profile on the Industrial Automation Exchange.