Human-Machine Interfaces (HMIs) are everywhere—from your smartphone to factory control panels. But even the best tech can fall flat if the design makes users want to scream. A great HMI should be easy to understand, quick to use, and pleasant to look at. Unfortunately, many designs miss the mark.
Let’s take a fun and simple look at the most common HMI design mistakes that can mess up user experience.
1. Too Much Stuff!
It’s tempting to show all the data at once. But when everything is important, nothing stands out.
- Overloaded screens make it hard to focus
- Users can’t find what they need fast enough
- It creates stress and confusion
Tip: Show only what’s relevant. Use layers or tabs for more detailed info.
2. Tiny Text & Buttons
If your users need a microscope to read your interface, we’ve got a problem.
- Small fonts are hard on the eyes
- Buttons too tiny to tap create frustration
- It’s even worse in industrial settings with gloves or shaky hands
Tip: Use readable fonts and big, clear buttons. Test them with actual users if possible.
3. Unclear Icons
Icons should help users navigate. But if your icons look like modern art, they’re not helping.
- Ambiguous icons confuse users
- Inconsistent symbols create learning curves
- Users may press wrong buttons and cause errors
Tip: Use well-known icons and pair them with short labels if needed.
4. Hidden Navigation
“Where’s that button?” is a question we don’t want users asking.
- Important functions should be easy to find
- Hiding actions in deep menus slows things down
- Users might miss critical steps
Tip: Keep navigation simple and visible. Prioritize common actions.
5. Bad Color Choices
Colors can guide the eye—or leave users feeling lost in a rainbow soup.
- Low contrast means users can’t see text clearly
- Too many colors cause visual overload
- Important alerts might blend in and go unnoticed
Tip: Use a clean color scheme. Red for errors, green for success—stick with universally known color meanings.
6. Too Many Confirmation Pop-Ups
Yes, safety is important. But do we really need to ask, “Are you sure?” five times?
- Too many warnings lead to users ignoring them
- Pop-ups interrupt workflow
- They make the interface feel slow
Tip: Save pop-ups for critical actions only. Trust the user with some freedom.
7. No Feedback
Ever click a button and wonder if it worked? That’s feedback failure.
- Interfaces should show a response to every user action
- No feedback makes users repeat actions unnecessarily
- This can lead to errors or frustration
Tip: Use sounds, animations, or visual changes to show that something happened.
8. Not Designing for Real Users
Designers often forget who will be using the HMI. It’s not always a tech expert in a clean office. Sometimes it’s a tired worker wearing gloves in a noisy, dusty factory.
- Different users have different needs
- Ignoring the real-world environment makes tools harder to use
Tip: Involve users early in the design. Watch them interact with prototypes. Gather feedback.
Wrap-Up
Designing a great HMI isn’t rocket science—but it does take thought. Avoid these common mistakes to create something that’s not only functional but also delightful to use.
Keep it simple. Make it clear. Test with real humans.
Your users (and their eyeballs) will thank you!
