Why HMI screen layout principles in SCADA systems? - Purpose & Use Cases

The Big Idea

What if a simple screen layout change could prevent costly accidents and save lives?

The Scenario

Imagine an operator in a factory trying to control machines using a cluttered screen filled with tiny buttons, confusing colors, and no clear order.

They have to hunt for the right control, often under pressure, risking mistakes.

The Problem

Manual screen design without clear layout rules leads to slow reactions, operator errors, and even safety hazards.

It's like trying to drive a car with a messy dashboard where you can't find the speedometer or brake pedal quickly.

The Solution

HMI screen layout principles guide how to arrange controls and information clearly and logically.

This makes it easy for operators to understand the system at a glance and act quickly and safely.

Before vs After

✗ Before

Screen with random buttons and colors, no grouping or priority

✓ After

Screen with grouped controls, clear labels, consistent colors, and prioritized alerts

What It Enables

It enables fast, accurate decisions by operators, improving safety and efficiency in industrial control.

Real Life Example

In a water treatment plant, a well-designed HMI screen helps operators quickly spot a pump failure and fix it before water quality drops.

Key Takeaways

Messy screens cause delays and errors.

Good layout principles make controls easy to find and understand.

This improves safety and speeds up operator response.

Practice

1. What is the main purpose of grouping related items together on an HMI screen?

easy

A. To make the screen look more complex

B. To make the screen easier to understand and use

C. To increase the number of buttons

D. To use more colors on the screen

Solution

1. Step 1: Understand grouping concept

   Grouping related items helps users find information quickly and reduces confusion.

2. Step 2: Consider user experience

   A clear layout improves safety and efficiency by making controls intuitive.

3. Final Answer:

   To make the screen easier to understand and use -> Option B

4. Quick Check:

   Grouping = Easier use [OK]

Hint: Group related controls for clarity and ease [OK]

Common Mistakes:

• Thinking more colors always improve clarity
• Adding too many buttons without grouping
• Ignoring user navigation needs

2. Which of the following is the correct way to label buttons on an HMI screen?

easy

A. Use clear, descriptive text like 'Start Pump 1'

B. Use vague terms like 'Start' without context

C. Use only icons without any text

D. Use random colors without meaning

Solution

1. Step 1: Identify labeling best practice

   Clear, descriptive labels help users understand button functions immediately.

2. Step 2: Avoid vague or confusing labels

   Labels like 'Start Pump 1' are better than generic or icon-only labels for clarity.

3. Final Answer:

   Use clear, descriptive text like 'Start Pump 1' -> Option A

4. Quick Check:

   Clear labels = Better understanding [OK]

Hint: Use clear text labels, not vague or icon-only [OK]

Common Mistakes:

• Using unclear or generic button names
• Relying only on icons without text
• Ignoring color meaning in labels

3. Consider this HMI screen layout code snippet:

screen = {
  'title': 'Main Panel',
  'buttons': [
    {'label': 'Start', 'color': 'green'},
    {'label': 'Stop', 'color': 'red'},
    {'label': 'Reset', 'color': 'yellow'}
  ]
}

What is the main issue with this layout?

medium

A. Button colors do not match their typical meanings

B. Button labels are too descriptive

C. The screen title is missing

D. There are too many buttons

Solution

1. Step 1: Analyze button colors and meanings

   Green for 'Start' matches (go/action), red for 'Stop' matches (danger/stop), but yellow for 'Reset' does not--yellow typically means caution/warning, not reset.

2. Step 2: Confirm other options

   Labels are simple (not too descriptive), title present, few buttons--issue is color mismatch.

3. Final Answer:

   Button colors do not match their typical meanings -> Option A

4. Quick Check:

   Colors should match meaning [OK]

Hint: Match button colors to their common meanings [OK]

Common Mistakes:

• Ignoring color conventions
• Assuming more buttons are always bad
• Overlooking screen title presence

4. You notice an HMI screen is cluttered with many controls and colors. What is the best way to fix this?

medium

A. Remove all labels to save space

B. Add more colors to differentiate controls

C. Group related controls and reduce color usage

D. Increase screen brightness

Solution

1. Step 1: Identify clutter causes

   Too many controls and colors make the screen confusing and hard to use.

2. Step 2: Apply layout principles

   Grouping related controls and limiting colors improves clarity and usability.

3. Final Answer:

   Group related controls and reduce color usage -> Option C

4. Quick Check:

   Less clutter = Better usability [OK]

Hint: Group controls and limit colors to reduce clutter [OK]

Common Mistakes:

• Adding more colors increases confusion
• Removing labels reduces clarity
• Changing brightness does not fix layout

5. You need to design an HMI screen for a complex system with many controls. Which approach best follows good layout principles?

hard

A. Use flashing colors to attract attention to all controls

B. Put all controls on one screen with random colors for each

C. Use only icons without labels to save space

D. Create multiple screens grouping related controls and use consistent colors

Solution

1. Step 1: Understand complexity management

   Complex systems require breaking down controls into manageable groups to avoid overwhelming users.

2. Step 2: Apply layout best practices

   Using multiple screens with grouped controls and consistent colors improves navigation and safety.

3. Step 3: Avoid poor practices

   Random colors, icon-only labels, and flashing colors cause confusion and reduce usability.

4. Final Answer:

   Create multiple screens grouping related controls and use consistent colors -> Option D

5. Quick Check:

   Group + consistent colors = Best design [OK]

Hint: Use multiple grouped screens with consistent colors [OK]

Common Mistakes:

• Trying to fit all controls on one screen
• Using random or flashing colors
• Relying only on icons without text