Industrial automation systems supervise hundreds, sometimes thousands of signals at once. Yet however advanced the technology, the final decision is still made by a human operator. Over the last decade the central question of SCADA/HMI design has shifted from "how much information can we show?" to "how do we deliver the right information, at the right time, in a form the operator instantly understands?" This philosophy is called situational awareness. The simple test: can your operator tell what is happening within 3 seconds of looking at the screen?
What is situational awareness?
First formalized in aviation by researcher Mica Endsley, it has three levels:
Perception — noticing what is happening now: which parameter left its range, which equipment is running.
Comprehension — understanding what it means and how it affects the process.
Projection — anticipating what comes next if the current trend continues.
A well-designed HMI lifts the operator beyond mere perception to comprehension and projection — often the difference between preventing an incident and reacting too late.
The problem with traditional SCADA screens
Traditional displays usually copy the P&ID directly: every pipe, valve and pump in bright colors, 3D effects, even animations. Attractive at first sight, but deeply flawed:
Everything is equally bright, so nothing stands out.
Normal and abnormal states look almost identical.
No "color reserve" is left for real emergencies — red is everywhere already.
Alarm floods: dozens of alarms fire at once and the root cause is lost.
A screen full of information is not the same as being well informed.
Traditional colorful screen vs situational-awareness-based design
Good design is measured not by how many colors it uses, but by how quickly the operator notices danger and makes the right decision.
Why the industry changed
This philosophy grew out of real accidents — Three Mile Island and the Texas City explosion among them — where analyses showed operators had not received the right information at the right time. The lessons produced international research and standards: the ASM Consortium, ISA-101 (the HMI standard for process automation), EEMUA 191/201, and *The High Performance HMI Handbook*. Studies confirm operators using High Performance HMIs detect abnormal situations several times faster and resolve them significantly sooner.
Ratios, not numbers
Reading "3.42 bar" forces recall and mental math. An analog indicator whose pointer sits inside the grey band says "normal" without reading at all:
Analog indicator states — normal, warning, alarm
Display hierarchy
Level 1 — plant overview: KPIs and overall status — "is everything normal?"
Level 2 — unit control: detailed operation of one process unit
Level 3 — equipment detail: a specific device or control loop
Level 4 — diagnostics: fault-finding, history, deep analysis
Benefits
Faster detection of abnormal situations, lower operator workload, built-in trends that show what is coming, faster and more confident decisions — and fewer errors and incidents overall.
Common misconceptions
"Grey screens look cheap" — in fact the grey base is a deliberate decision to direct attention. "More colors and 3D = more advanced" — cognitive science shows the opposite. "It's just aesthetics" — it is engineering grounded in cognitive research. Operators often call the new screens "boring" at first, then admit they spot problems earlier with less eye strain.
Conclusion
Situational awareness is not about looking nice — it is about helping the operator make the right decision at the right time. On projects like the Tavantolgoi logistics centre, Energy Resources' coal-handling plant and Erdene Mongol's gold processing plant, our team designs interfaces that genuinely support decisions, not just display values. However far the technology advances, the system's true "interface" is still the human being.
Get a free assessment of your current SCADA screens: 7733-4478 or talk to the AI assistant on this site.