In oil and gas, an operator can go from “all good” to “shut it down now” in seconds. At that moment, the HMI or SCADA screen isn’t decoration, it’s the operator’s lifeline.

A clean, structured display helps them spot an abnormal condition, understand it, and act before it becomes downtime, equipment damage, or a safety event.

A cluttered display does the opposite: it slows recognition, buries the real problem, and adds stress right when clarity matters most.

This is measurable. High-performance HMI programs have been shown to help operators detect abnormal situations more than five times faster and intervene in time to prevent escalation far more consistently.

Those gains don’t come from prettier graphics. They come from disciplined layout, predictable navigation, and clear visual hierarchy rooted in how people actually see and think.

Standards such as ISA-101, NUREG-0700, and ISO 11064 exist for exactly that reason. 

ISA-101, for example, focuses on consistency, navigation, alarm clarity, and situational awareness so operators can read plant status at a glance and respond correctly under pressure.

These aren’t academic guidelines. They’re field-tested practices that have improved reliability and reduced incident rates across process industries.

This guide breaks down the core layout principles you need to apply if you want your HMI/SCADA screens to function as decision tools, not just data wallpaper.

Humans don’t scan a page like a spreadsheet. Vision works in two stages.

Stage 1: Preattentive Processing

First is “preattentive” processing — the brain sweeps the screen and flags something that looks wrong (a color shift, an odd shape, a bar out of range) in a few hundred milliseconds. Research in visual cognition puts that early sweep in roughly the 200–500 millisecond window, before we’re even fully aware we’re looking. After that comes focused attention, which is slower and takes mental effort.

Good HMI design uses that biology. True problems should stand out instantly, even in peripheral vision. Routine values should fade into the background until needed. When every value is loud, nothing is urgent. That forces operators to spend energy sorting noise from signals instead of deciding what to do.

Stage 2: Cognitive Load

Cognitive load is the second limiter. People can only process so much at once. Once you blow past that limit performance doesn’t just dip slightly. For example, dumping fifty unrelated tags, flashing colors, and stacked trends into one view.

It collapses. Modern “high-performance HMI” layouts respond to that by using muted graphics, limited color, and exception-based displays instead of “everything everywhere.”

If you want better performance, track it. The most useful commissioning and operations KPIs for HMI/SCADA screens are:

• Recognition time — How fast does the operator notice that something is wrong? For top-tier consoles, the goal for a critical alarm is under about three seconds.
• Diagnosis time — How fast can they explain what’s happening and why? Well-structured overview screens with proper context routinely get operators to a working mental model in under 30 seconds for common upsets.
• Action initiation time — How long before corrective action starts?
• First-time success — Did they choose the correct response without guessing or bouncing through five menus?

Plants that shorten recognition/diagnosis time and increase first-time success see fewer unplanned slowdowns and fewer “near miss” safety events. Those improvements show up as shorter abnormal events and less time running equipment outside ideal limits — which is real money.

Operator fatigue is another metric worth watching. Screens that make people hunt, squint, and cross-reference constantly drive fatigue, and fatigue drives mistakes. An HMI that reduces searching and makes state obvious at a glance is a reliability tool, not a cosmetic upgrade.

Classic SCADA graphics tried to recreate a P&ID on the screen: every pump, every line, every tag. High-performance HMI takes the opposite view. Operators don’t need every detail all the time. They need to know: Are we healthy? If not, where’s the problem? What should I do next?

ISA-101 formalizes that approach. The standard calls for HMIs that support situational awareness — the operator can tell what state the system is in, predict where it’s headed, and access the right control fast enough to intervene. Three themes show up again and again:

1. Clarity. Graphics are intentionally simple, often grayscale, so real problems pop instead of drowning in gradients and 3-D art.
2. Consistency. Navigation, alarm areas, and key status indicators live in the same place on every screen and across process units.
3. Progressive disclosure. High-level overviews show overall health. From there, the operator drills down (unit → train → equipment) to get detail only when it’s actually needed.

This mindset is about cognitive efficiency, not “nicer look and feel.” You are preserving the operator’s attention for judgment instead of forcing them to search for controls.

Screen Zoning

ISA-101 encourages standard screen zoning. Put the most critical live status (pressures, levels, flows, permissives, trips) front and center, usually top-middle, because eye-tracking work shows that’s where operators naturally look first. 

Secondary data like controller states, supporting KPIs, and short trends sit nearby but do not compete for attention. Navigation and common actions occupy fixed bands along an edge (often top or left) so nobody has to hunt for them in a crisis.

Once that frame is set, copy it everywhere. The benefit is predictability. During an upset, the operator’s eyes and hands already “know” the layout.

Information Hierarchy

Not all data is equally urgent. Treat it that way.

• Primary information is anything tied to safety, regulatory compliance, or staying online. It earns prime placement, bigger text, and the strongest visual cues.
• Secondary information is used to optimize production, energy use, or product quality. Keep it visible but calmer.
• Tertiary information is diagnostic context. It should be one click away, not stuffed onto the main overview.

This hierarchy stops the “wall of numbers” effect and lets the operator build a reliable mental checklist: look here first for safety, here second for throughput, here third for troubleshooting.

Alarm and Event Visibility

Alarms should live in a dedicated, always-visible band — often along the bottom or side — instead of floating over graphics. Critical trip conditions and standing alarms can’t be allowed to hide behind popups. The alarm band is not decoration; it’s a reserved lane for “act now” information.

Equally important: alarm navigation and acknowledgment controls belong in the same place on every screen. Muscle memory matters when the room is loud, people are talking, and time is tight.

White Space Isn’t Wasted Space

One of the fastest ways to sabotage an interface is to pack every inch with numbers and mini-trends. Overdense screens force operators to mentally sort and group information before they can even think about action.

Give the eye breathing room. Use spacing and subtle grouping (borders, light shaded panels, proximity) to show which values belong together. White space is how an operator instantly reads “these four values are one subsystem” without having to stop and decode.

Color: Treat It Like a Siren, Not Wallpaper

High-performance HMI guidelines intentionally limit color. Red is “danger/emergency,” yellow is “abnormal/caution,” green is “normal/safe,” blue is “advisory.” Everything else stays neutral for two reasons:

• If the whole screen is bright, nothing looks urgent.
• Color alone is unreliable. 

Roughly 8% of men (and a much smaller share of women) have red-green color vision deficiency, which means a pure “red vs. green” signal can literally vanish for them. Good screens back up color with shape, label, location, or icon.

Also consider lighting and age. Control rooms are rarely perfect viewing environments. High contrast between text and background keeps values readable on older monitors, through glare, or under emergency lighting. Try using 7:1 or better.

Typography and Icons

Readable beats stylish. Use clean sans-serif fonts with clear shapes. Make sure normal operating values can be read from a typical console distance without leaning in, and make critical states larger and bolder.

Keep the typography rules consistent across the system so “critical,” “normal,” and “caution” always look the same wherever they appear.

For symbols, stick to standard ISA / ISO process icons so a pump looks like a pump and a valve looks like a valve no matter who’s on shift.

Build an icon library, document it, and require everyone to use it. Consistency here pays off in faster recognition and fewer “what am I looking at?” questions.

Navigation and Information Architecture

Think like an operator, not like a PLC rack. Menus should mirror how the plant is actually run: “Train A Overview,” “Compression,” “Produced Water Handling,” “Flare,” etc., not just controller names. That keeps navigation aligned with real tasks.

Within that structure, breadcrumb trails or on-screen location indicators tell the operator, “You’re in Injection Pumps → Pump B Detail.” That orientation matters when they’re drilling down fast to troubleshoot a trip.

High-risk actions need direct, consistent access; like shutdowns, bypasses, and permissive overrides. Do not bury them three clicks deep in a submenu that looks different in each unit. That’s how hesitation and mis-clicks happen during high-adrenaline moments.

A style guide is non-negotiable if you want long-term consistency. It should lock in:

Screen zoning (what sits where)

• Color and alarm priority rules
• Font families and sizes
• Icon library and naming
• Navigation layout and breadcrumb rules
• Alarm banner behavior and acknowledgment path

Treat that guide like any other engineering standard, not an optional branding exercise.

Before you call a design “done,” hand it to actual console operators and run realistic scenarios. Include both steady-state work (normal operation, minor adjustment) and stress situations (pressure spike, trip, environmental exceedance). Time how long it takes them to notice the problem, explain what’s happening, and start the right response.

Capture the numbers: recognition time, navigation errors, first-time success rate. Compare new screens to legacy ones. The plants that close this loop — design, test, adjust — see smoother startups, faster abnormal response, and fewer commissioning surprises.

Screen layout is not cosmetic. It is an operational control layer. The difference between a disciplined, ISA-101 style layout and a legacy “copy of the P&ID” graphic shows up in abnormal event duration, alarm floods, and stress on the person keeping the asset online.

The path forward is straightforward:

1. Audit what you currently display. Where are the alarms? Where does the eye land first? Where are people wasting time hunting?
2. Write or update your HMI style guide. Lock in zoning, colors, typography, icons, navigation, and alarm behavior.
3. Pilot the new layout on one unit or console. Train the operators who will live with it. Measure before/after performance.
4. Roll out in phases, keep gathering feedback, and treat operator input like instrumentation data — objective and actionable.

Do this and your HMI stops being a noisy wall of data. It becomes what it should be: a fast, reliable decision aid that helps the operator keep the plant safe, compliant, and productive — even on the worst day of the year.