Core Principles for Effective HMI Design in Manufacturing

Every time an operator acknowledges an alarm, changes a setpoint, or starts a batch, they do it through a human-machine interface (HMI). The quality of that interface shapes how quickly they spot a problem, how confidently they respond, and how often a simple misread turns into a deviation or a safety event. HMI design is where engineering meets human factors, and it has a direct effect on productivity, safety, and operating cost across industrial operations.

Yet many engineers who build HMI screens have never been formally taught how to design them. Platform training explains how to configure graphics in a specific SCADA or DCS tool, but rarely why one layout works and another fails under pressure. This guide covers what HMI training typically includes, the core principles of effective HMI design, the standards that govern it, and the practical questions designers, engineers, and system integrators should ask when building or modernizing an interface.

What Is HMI Design?

HMI design is the practice of creating the interfaces through which people monitor and control industrial machines and processes. An HMI can be a touchscreen panel mounted on a single skid, a SCADA workstation overseeing an entire utility system, or a distributed control system (DCS) operator console in a central control room. In every case, its job is the same: turn thousands of data points into information an operator can understand and act on.

Good HMI design goes well beyond making screens look modern. It decides what information appears, at what level of detail, in what order, and how abnormal conditions are brought to the operator’s attention. It also determines how commands are entered, confirmed, and recorded. In manufacturing, where a single operator may be responsible for dozens of units or an entire production line, those decisions directly affect how well processes are monitored and controlled.

It helps to separate HMI design from HMI configuration. Configuration is the technical work of building graphics, linking tags, and setting up navigation in a specific software package. Design is the upstream thinking that decides what those graphics should be and why. Both matter, but design is the part most often learned informally, and the part most often responsible for an interface that technically works but is hard to use.

Why HMI Design Matters in Industrial Automation

HMI systems play a pivotal role in industrial automation because they are the point where human judgment and automated control meet. Automation handles the routine; operators handle the exceptions. When a process drifts, alarms start to flood in, or equipment behaves unexpectedly, the HMI is what the operator relies on to understand the situation and decide what to do next.

Well-designed HMIs support faster, more accurate decisions, which translates into higher productivity, fewer errors, less unplanned downtime, and safer operations. Poorly designed HMIs do the opposite. Cluttered screens bury the information that matters, inconsistent layouts force operators to relearn each display, and alarm overload makes it harder to recognize the one alarm that truly needs action. Investigations into major process incidents have frequently identified ineffective alarm systems as a contributing factor, which is one reason alarm presentation is treated as a core part of HMI design rather than an afterthought.

There is also a cost dimension. Reworking a poorly designed HMI after commissioning, retraining operators who have built habits around it, and investigating the errors it contributes to are all far more expensive than designing it well from the start. That is why HMI design is increasingly treated as a skill worth developing deliberately, rather than something picked up on the job.

What Does HMI Training Cover?

HMI training teaches engineers, designers, and system integrators how to create interfaces that operators can use effectively under both normal and abnormal conditions. Where software-specific courses focus on building screens in a particular platform, HMI design training focuses on principles that apply regardless of vendor. A well-rounded course typically covers:

• •    Human factors engineering: how people perceive, process, and respond to information, and how fatigue, stress, and workload affect performance.
  •    Display hierarchy and navigation: structuring screens from area overviews down to detailed equipment and diagnostic views so operators can move between them intuitively.
  •    Color, layout, and visual design: using muted backgrounds and reserving strong color for abnormal conditions so problems stand out immediately.
  •    Alarm presentation: how alarms are displayed, prioritized, and acknowledged in line with alarm management practice.
  •    Industry standards: the HMI lifecycle described in ANSI/ISA-101.01, including the HMI philosophy, style guide, and reusable object library.
  •    Usability and performance: evaluating designs with real users and measuring whether an interface supports the tasks it was built for.
  •    Integration and security: how HMIs connect to control systems and wider networks, and what that means for access control and cybersecurity.

The most useful courses connect these topics to real industrial scenarios, so learners can see how a design choice plays out on an actual process rather than in the abstract.

Six Key Principles of Effective HMI Design

Most HMI design guidance, including the ISA-101 standard, comes back to a handful of core principles. Each one addresses a specific way an interface can help, or hinder, the people using it.

1. Simplicity and Clarity

Design interfaces that are intuitive and easy to navigate, so operators can find what they need without hunting for it. Every element on a screen competes for attention, so anything that does not support a decision or an action should be questioned. Decorative 3D graphics, unnecessary animation, and raw numbers without context all add visual noise.

Clarity also means presenting information in a form that supports interpretation. A trend showing where a value is heading, or an indicator showing whether it sits inside its normal operating range, often tells an operator more than a number alone. The aim is to reduce the mental effort needed to understand the process, which reduces errors and improves productivity.

2. Consistency

Maintain uniformity across every display: the same symbols, colors, fonts, button placements, and navigation patterns should mean the same thing everywhere. When a pump looks and behaves the same on every screen, operators build reliable habits and become proficient faster, which shortens training time and reduces the chance of misreading an unfamiliar display.

In practice, consistency comes from a documented HMI style guide and a reusable library of display objects. These are especially valuable on large or multi-site projects, where several engineers or integrators may be building screens at once, and over the life of a system, as new displays are added years after the original design.

3. Visibility

Make sure the information operators need is visible without clutter, so they can maintain situational awareness and make quick decisions. Key process values, equipment states, and active alarms should be available at a glance, not hidden several clicks deep.

A common approach is a display hierarchy that moves from a high-level overview of an area, through unit and equipment displays, down to detailed diagnostic views. The overview tells the operator whether anything needs attention; the lower levels provide the detail needed to act. Getting this structure right is one of the most effective ways to improve how quickly operators detect and respond to abnormal situations.

4. Feedback

Provide immediate, clear feedback for every operator action, confirming that a command has been received and executed. If an operator opens a valve or changes a setpoint, the interface should show the requested state, the actual state, and any discrepancy between the two.

Missing or ambiguous feedback is a common source of error. Operators who are unsure whether a command registered may repeat it, escalate unnecessarily, or move on assuming an action succeeded when it did not. Clear feedback builds trust in the system and keeps the operator’s mental picture of the process aligned with reality.

5. Accessibility

Design with every potential user in mind, so the interface works for operators across a range of abilities, experience levels, and working conditions. That includes viewing distance, lighting, screen glare, and whether operators will be wearing gloves or other protective equipment.

Color deserves particular attention. Because some users have difficulty distinguishing certain colors, status and alarm information should never depend on color alone; pairing it with shape, text, position, or symbols makes the meaning clear to everyone. Accessible design is simply good design: an interface that is easy for one group to use tends to be easier for everyone.

6. Error Handling

Build in features that minimize the impact of errors, either by preventing them before they happen or by making recovery straightforward afterward. Prevention can include confirmation steps for critical commands, limits on allowable setpoint ranges, and interlocks that block unsafe sequences.

Recovery matters just as much. Clear messages explaining what went wrong and what to do next help operators correct course quickly, while well-structured alarm and event logs make it easier to understand what happened after the fact. The goal is not to make operators wary of the interface, but to make the safe action the easy one.

HMI Design Standards: ISA-101 and IEC 63303

ANSI/ISA-101.01-2015, Human Machine Interfaces for Process Automation Systems, is the most widely referenced industry standard for HMI design, particularly in North America. Published by the International Society of Automation (ISA) in 2015, it covers the philosophy, design, implementation, operation, and maintenance of HMIs for process automation systems, and defines the terminology, models, and work processes needed to manage an HMI across its full lifecycle.

A central idea in ISA-101 is that consistent HMIs come from documented decisions. The standard describes an HMI philosophy, which sets out guiding principles for a site or organization, and a style guide, which turns those principles into specific rules for layout, color, navigation, and display objects. ISA has since published supporting technical reports, including ISA-TR101.01 on HMI philosophy and ISA-TR101.02 on HMI usability and performance, which give practical guidance on applying the standard.

Internationally, the International Electrotechnical Commission (IEC) published IEC 63303:2024, Human machine interfaces for process automation systems, which was developed from ISA-101. It defines general structures and functions of HMI systems, includes an example HMI lifecycle, and sets out requirements and recommendations for designing, using, and maintaining HMIs, including recommendations on user training. That makes it increasingly relevant for European and global operations.

Two related standards are also worth knowing. ANSI/ISA-18.2 covers lifecycle management of alarm systems, which shapes how alarms should be presented on the HMI, and the ISA/IEC 62443 series addresses security for industrial automation and control systems, including the HMIs connected to them. Note that ISA-101 was written primarily for process automation; machine-level HMIs built by OEMs often have different needs, and ISA has set up working groups to address machine control and mobile HMIs.

Applying HMI Design Principles in Practice

Start With the Operator’s Tasks

Effective HMI design begins with understanding who will use the interface and what they need to accomplish. Analyzing user requirements means looking at the specific tasks, workflows, and decisions operators face during normal operation, startup, shutdown, and abnormal situations, then designing displays that support those tasks directly.

Techniques such as task analysis, operator interviews, and observation of existing workflows reveal where current interfaces cause friction. An HMI organized around how operators actually work, rather than around how the control system happens to be structured, is far more likely to be used as intended.

Design Iteratively and Test With Real Users

An iterative design process, using feedback from real-world testing, is the most reliable way to refine an interface. Early mock-ups and prototypes let operators react to layouts before significant configuration effort has gone in, while changes are still inexpensive to make.

Usability testing with representative users, ideally against a simulated process, shows whether operators can find information and complete tasks as quickly and accurately as the design intends. Feedback from these sessions, and from operators once the system is live, should flow back into the style guide so improvements carry forward to future displays.

Integrate With Existing Systems

HMIs rarely exist in isolation. They draw data from PLCs, DCS controllers, and historians, and increasingly from manufacturing execution systems (MES) and enterprise platforms. Designing with integration in mind improves interoperability and avoids interfaces that present conflicting or duplicated information.

Integration has a human side too: new displays should fit the conventions operators already know, or the transition should be planned deliberately when those conventions change. Following ISA-101 guidance throughout helps ensure the resulting interface is effective, efficient, and reliable.

HMI Design in Regulated Life Sciences Manufacturing

In pharmaceutical and biotech manufacturing, HMI design carries extra weight because the interface is part of the validated control system. Operator actions taken through the HMI, such as setpoint changes, alarm acknowledgments, and batch operations, can form part of the electronic record that supports product quality decisions.

Where FDA 21 CFR Part 11 applies, that brings considerations such as unique user logins, role-based access levels, secure audit trails of operator actions, and electronic signatures where records require them. Design choices that seem minor in other industries, such as how a user confirms a critical command or how shared accounts are avoided on a local panel, can have real data integrity implications in a GMP environment.

Clear, consistent HMIs also support compliance indirectly. Interfaces that reduce operator error help reduce deviations, and displays that align with standard operating procedures make it easier for operators to follow them as written. For regulated manufacturers, HMI design and validation planning work best when they happen together rather than one after the other.

Selecting the Right Software and Hardware for HMI Design

HMI Software

The core software for HMI design and deployment is usually a SCADA or DCS visualization environment for building and running process graphics. Computer-aided design (CAD) tools help create accurate graphical models of equipment, and simulation software allows interfaces to be tested and refined against a virtual process before real-world deployment.

When choosing software, compatibility comes first: it must integrate smoothly with the controllers, historians, and other applications the HMI interacts with, and scale as needs evolve. Support for reusable object libraries and templates makes it much easier to enforce a consistent style guide. It is also vital to assess the vendor’s support and update policies, including how security patches are delivered, to keep the system reliable and secure over time.

HMI Hardware

Industrial HMI hardware has to withstand conditions office equipment never sees. Screens, panels, and input devices such as touchscreens, keyboards, and trackballs need to resist dust, moisture, temperature extremes, and vibration. In life sciences cleanrooms and washdown areas, hardware may also need sealed enclosures, surfaces that tolerate repeated cleaning, and touchscreens that respond reliably to gloved hands.

The right hardware keeps HMIs operational and efficient under tough conditions, reducing downtime and maintenance costs. Location matters as well: a fixed control room console, a panel mounted beside equipment, and a handheld or mobile device each place different demands on screen size, readability, and how much information a single display should carry.

Technology Trends Influencing HMI Design

Adaptive Interfaces

HMIs are increasingly adaptive, adjusting what they show based on the user’s role, the current operating state, or the task at hand. A maintenance technician and a process operator may see different views of the same equipment, and a display might surface additional detail automatically when a unit moves into startup or an abnormal condition.

Done well, adaptive interfaces reduce clutter by showing each user what is relevant to them. Done poorly, they undermine consistency and make it harder for operators to predict where information will appear. The same design principles still apply: adaptation should be predictable, documented in the style guide, and tested with real users.

Augmented Reality (AR)

Augmented reality offers a new way to visualize and interact with industrial systems. Instead of walking back to a fixed screen, an operator or technician using a headset or tablet can see real-time process data and step-by-step guidance overlaid directly on the equipment in front of them.

AR is especially promising for training, maintenance, and troubleshooting, where seeing information in context reduces the need to switch between the equipment and a separate display or manual. It carries established HMI principles into a new medium: clarity, consistency, and clear feedback matter just as much in a headset as on a panel, and arguably more, given how close the information sits to the user’s field of view.

Increased Focus on Cybersecurity

As HMIs become more connected to plant and corporate networks, securing them is essential to prevent unauthorized access and protect system integrity. An HMI is often the most direct route for issuing commands to a process, which makes it both an attractive target and a critical point of control.

Practical measures include strong authentication, role-based access, network segmentation between enterprise and control networks, timely patching, and disabling unused services and ports. The ISA/IEC 62443 series is the most widely recognized framework for securing industrial automation and control systems, and HMI designers benefit from understanding how its requirements shape interface decisions such as login flows and remote access.

Questions to Ask During the HMI Design Process

Asking the right questions early prevents costly redesigns later. Designers and project teams might consider:

• How will this interface improve operational efficiency for the people using it?

• Is it intuitive enough to support quick, accurate decisions under pressure?

• What are the safety implications of each design choice, particularly for critical commands?

• Where will the HMI be located? Is it fixed, or handheld and portable?

• Who are the users, and how do their roles, experience levels, and tasks differ?

• How will alarms be prioritized and presented?

• How will the design be kept consistent and maintained as the system changes?

Integrating new technologies into an existing HMI system raises a few more factors. Compatibility with existing systems determines whether the new technology will function smoothly within the current setup. The learning curve for operators must be manageable to avoid disrupting daily operations. Teams should also consider whether the change will improve existing workflows or introduce friction, confirm that the system architecture can support the integration, and assess any cybersecurity risks the new technology might introduce or expose.

Why Formal HMI Design Training Is Worth It

Proficiency in HMI design is valuable for anyone involved in developing or maintaining industrial systems. Automation and controls engineers who configure HMIs, system integrators delivering projects across multiple sites, OEMs building machine-level interfaces, and operations or quality leads who review and approve displays all benefit from a shared understanding of what good design looks like.

Because so much HMI work is learned on the job, knowledge is often inherited from whoever built the previous system, along with its habits and shortcomings. Structured training breaks that cycle. It gives teams a common vocabulary, grounds design decisions in human factors and recognized standards, and makes it easier to build interfaces that work with operators rather than against them.

When evaluating an HMI course, look for coverage of human factors engineering, display styles and hierarchy, alarm presentation, performance considerations, and current standards such as ISA-101. Vendor-neutral content is especially useful, since the principles apply whichever platform your site runs.

Horizon Controls Group offers a Fundamentals of Human-Machine Interface Design course for manufacturing industry professionals, covering human factors engineering, HMI display styles, performance factors, and current industry standards, from basic principles through to advanced system management.

If you would like to know whether it is the right fit for your team, get in touch to find out more.