Human vs. Machine: Why Good HMI Design Makes All the Difference

One of the core designs of any product, whether it be a video game menu, your phone’s operating system, an HMI, or the laptop used to program it, is its User Interface. The UI, by definition, is the space where interactions between humans and machines occur, and is especially important to get right as it’s what stands between you and the task at hand. If executed poorly, this will lead to user frustration, anger, and reduced willingness to use it. After all, would you still use a phone if you had to jump through five menus every time just to unlock it? Of course not. The same human-centric design principle applies to industrial Human-Machine Interfaces as well. So let’s get into what makes an HMI design great and why it matters to the operator using it!

What is a Bad HMI Design and How to Work Around It

A bad HMI UI design is easier to recognize because it stands out much more. This can lead to operator error, misinterpreted information, or downtime if it is severe enough. Some of the more common poor UI choices for HMIs are:

Cluttered Displays

A cluttered display can result from many poor UI choices, such as mismatched fonts, too much information on the screen, misaligned components, or everything being highlighted. This can cause information overload for the operator. An example of this is a screen with highlighted text boxes and numerical values for six elements, each corresponding to a different motor. Sure, an operator can take a look and pick out the information they need. Still, a cleaner solution would be to use tabs, alignment tools, and symbols to convey information visually. A motor, its corresponding pump, and valve can each have a different, distinguishable symbol that is easier to recognize at a glance, saving the operator time.

Inconsistent Fonts and Themes

A poor UI often shows an inconsistent theme across its screens. Different fonts, colors, font sizes, underlines, and highlights can confuse the operator. Using styles and themes throughout the HMI UI could dramatically improve readability and, once more, save the operator time finding what they’re looking for.

Traditional HMI Design

A traditional HMI UI is typically thought of as screens with graphics from Windows Vista-era software. A bit bulky, sometimes visually noisy, outdated, and cluttered. A high-performance HMI reduces graphics in favor of a less busy, minimalist design, with the intent of making each symbol recognizable without too much noise, leaving more room for the operator to read its status in the shortest time. This usually involves more gray-scale screens with flat components rather than the brighter, multicolored traditional designs.

Non-Scalable Screens

A HMI UI design might look great on a web browser, but when transferred to a panel or mobile device, it can be cut off if the designer isn’t careful. This leaves the issue of information being out of the operator’s view. There are many workarounds for this, such as flexible designs that allow the screen to alter its components’ height and width when transferring to mobile, using coordinate components that change the size and location of components relative to a parent size and location, or breakpoint designs that allow for two screen layouts depending on whether the operator is on mobile or web.

Too Much Color

With traditional HMI designs that you might find in a factory that hasn’t updated its UI in decades, colors are everywhere. It was simply a design choice for that era, and seasoned operators are used to it. However, the problem is that the eye doesn’t know where to look when you have a dozen different elements in varying colors. Now, using color can absolutely make an HMI design look modern when implemented strategically and thoughtfully. A color scheme that matches a company’s logo can look very nice, that is, if the colors aren’t too offensive to the eyes. A consistent color theme with few changes or bright colors, while reserving reds for alarms, is ideal. A good designer knows how to draw a user’s eye to an important element with color.

Complex Navigation Schemes

Sometimes a company will add elements that lead to new pages on the older ones as they deem necessary, but doing this too much can create a very complex navigation map that can confuse the operator when they need to use it. Pages that loop back on themselves, unreachable pages, and other frustrating elements where the operator doesn’t know how to get back to the screen they want can cost a lot of time. A designer should implement a clean navigation system that has well-defined elements that allow the operator to navigate horizontally and laterally with ease.

How a Good Design Makes a Difference

A well-designed HMI does not just make the operator’s job easier. It changes how the entire system behaves day to day. When an interface is clear, predictable, and easy to read, operators spend less time figuring out what the machine is doing and more time responding to what actually matters. Those time savings show up in ways that are easy to overlook but expensive to ignore.

Easier to Use

For an operator, a good HMI reduces stress. Instead of constantly scanning the screen, second-guessing values, or navigating through layers of pages, they can quickly understand the machine’s current state. Is it running normally? Is something trending in the wrong direction? Is an alarm actionable or just informational? When those answers are obvious, operators can make decisions with confidence rather than hesitation.

Downtime Prevention

This directly impacts downtime. In many facilities, the longest part of an outage is not the fault itself, but the time it takes to identify what went wrong. A clean HMI that clearly labels faults, highlights affected equipment, and provides contextual information helps operators pinpoint issues faster. That means quicker resets, fewer unnecessary stops, and less time waiting for maintenance to arrive to diagnose the problem.

Error Prevention

Good design also helps prevent errors before they happen. Clear labeling, consistent button behavior, and intuitive navigation reduce the risk of pressing the wrong control or misinterpreting a value. When actions are deliberate and obvious, operators are less likely to make mistakes that lead to damaged equipment, scrapped product, or safety incidents. Over time, this translates to more stable operation and fewer costly recoveries.

From the company’s perspective, a strong HMI design improves efficiency across shifts and experience levels. New operators ramp up faster because the interface makes sense without extensive explanation. Veteran operators stay productive because cluttered or confusing screens do not slow them down. Training time is reduced, handovers are smoother, and tribal knowledge becomes less critical when the interface itself communicates clearly.

Final Thoughts

Ultimately, a good HMI design protects uptime. It helps machines recover faster, operators work more confidently, and teams respond to issues with clarity instead of confusion. While it may seem like a small piece of the overall system, the interface is where humans and machines meet. When that interaction works smoothly, the entire operation benefits. While the design is important, its also good to know other ways that HMIs can improve industrial automation processes, so we made an article here going over that and more to check out!

If HMIs are what you’re looking for, then we have you covered. We carry PanelView, VersaView, Harmony GTO, and more. We also offer repair services if you would like to have your old or broken HMI brought back to life, all backed by our two-year warranty. Give us a call today to see what we can do for you!