Secrets of effective HMI design

Creating an interface that’s effective and efficient, and maybe it will look nice too.

10/05/2012


Over the course of my career, I have seen hundreds of different HMI applications. Some of them have been very good, while some of them have been painful to look at and worse to actually use. The most important purpose of an HMI application is to allow an individual to interface with the control system as effectively and efficiently as possible. When developing an application from start, I break the development process into two parts: functionality and layout. 

Fulfilling specific functionality needs is really why an HMI will be developed. Ideally, the functionality required from the HMI would be clearly defined in the project functional specification or similar document. In instances where the functionality requirements are absent or poorly defined, the developer must communicate with the customer to define the scope prior to starting the HMI development process. 

You might think the application’s functionality would determine if a project was considered a good HMI or a bad one, but I disagree. The functions the HMI will perform are defined by the scope and therefore should be included in a good and bad design either way. As a matter of fact, I would say that an application that provides more or less functionality than required would be a bad design. An effective HMI design provides an individual operator with the necessary functions quickly and easily. 

In the world of the Internet, there are many websites that provide the same set of functions. I’m sure you have favorites that you use for weather forecasts, sports scores, stock quotes, etc. Did you ever think about why you tend to choose a certain website over another? For these simple tasks, each of the websites will provide the same data, and a lot of time it is from the same sources. The appeal of a certain website over another is probably not the functionality or data it is providing, but simply the layout or your positive user experience of the website. 

In the same way, the secret to an effective HMI design is also the layout. In my experience, most project scopes include a lot of functionality requirements but very little about layout requirements. For example, let’s say a functional specification includes a requirement to set a bit in the control system using a button, but there may be no requirements about the button itself. Ultimately, both a good or bad overall design will have some sort of button that sets the value. However, what really sets the good and bad apart is the look, location, consistency, labeling, background colors, text sizes, navigation schemes, and so on.  

Here are a few simple guidelines I keep in mind when developing a new HMI project:

1. Just because it looks good to you does not mean it will look good to the user. Remember, you are developing the application for someone to use every day, so it is not the time to use your favorite orange background and yellow text colors. Use color standards that contrast each other well. Review the published standards for proper color use.

2. Every object or function does not need to be on the main graphic. Too many times I have seen a project where a designer wants to fit as many objects as possible on one graphic. Those extra items can very easily inhibit an operator’s ability to see what is really important. Effective use of space is very important.

3. Navigation should be simple and effective. If the project is large, use both global and local navigation schemes. Group by process, area, device category, geographic location, or whatever makes the most sense for your application. The thing to remember is the user should not have to drill down more than two or three levels to get to any function. On the other hand, if the project is simple, keep it simple. Don’t use a different graphic for each function; instead separate a graphic into multiple areas with effective use of lines, boxes, or some other method within the graphic.

4. Keep consistency throughout the design. All of the components that create the final layout should be similar to one another. For example, all text objects should be the same font, color schemes, and size. Any header or navigation areas should be the same size and position on all graphics. 

5. Finally, schedule frequent graphic reviews with an authorized representative of the customer. The customer should have the final approval over all details of the HMI project. Remember, you are developing the project for the customer, not yourself. Final presentation of the graphics is not the time you want to learn that the customer had something else in mind. 

The tips here may seem like common sense to most you and hopefully you follow standard practices. Unfortunately, I have seen a blue and yellow HOME button on the lower left corner of one graphic, and a grey and purple HOME button on the upper right of the next. 

Stay tuned to future discussions where we will take a more in-depth look at these tips and more.

This post was written by William Zupon. William is a senior control systems specialist at MAVERICK Technologies, a leading system integrator providing industrial automation, operational support and control systems engineering services in the manufacturing and process industries. MAVERICK delivers expertise and consulting in a wide variety of areas including industrial automation controls, distributed control systems, manufacturing execution systems, operational strategy, and business process optimization. The company provides a full range of automation and controls services – ranging from PID controller tuning and HMI programming to serving as a main automation contractor. Additionally MAVERICK offers industrial and technical staffing services, placing on-site automation, instrumentation and controls engineers.



No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
World-class maintenance: The three keys to success - Deploy people, process and technology; 2016 Lubrication Guide; Why hydraulic systems get hot
Your leaks start here: Take a disciplined approach with your hydraulic system; U.S. presence at Hannover Messe a rousing success
Hannover Messe 2016: Taking hold of the future - Partner Country status spotlights U.S. manufacturing; Honoring manufacturing excellence: The 2015 Product of the Year Winners
The digital oilfield: Utilizing Big Data can yield big savings; Virtualization a real solution; Tracking SIS performance
Getting to the bottom of subsea repairs: Older pipelines need more attention, and operators need a repair strategy; OTC preview; Offshore production difficult - and crucial
Digital oilfields: Integrated HMI/SCADA systems enable smarter data acquisition; Real-world impact of simulation; Electric actuator technology prospers in production fields
Improving flowmeter calibration; Selecting flowmeters for natural gas; Case study: Streamlining assembly systems using PC-based control; CLPM: Improving process efficiency, throughput
Putting COPS into context; Designing medium-voltage electrical systems; Planning and designing resilient, efficient data centers; The nine steps of designing generator fuel systems
Warehouse winter comfort: The HTHV solution; Cooling with natural gas; Plastics industry booming

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
This article collection contains several articles on the vital role that compressed air plays in manufacturing plants.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me