Author: Olga Zinoveva, Senior Software Engineer, Bright Machines
From the physical push buttons, lights and switches of the 1980s, to the multi-touch screens of today, Human-Machine Interfaces (HMIs) have evolved over the last few decades. However, as someone with a background in software engineering for games and consumer applications, I’ve noticed many opportunities to replicate best practices from the User Design (UX) discipline in the consumer technology sector on the factory floor.
Whether a professional designer or not, we can all identify impactful UX. Think about the change from button-based phones and keyboard-only interfaces to powerful, easy-to-use, touch-based smartphones and tablets. This evolution of interfaces created new interaction models and UX paradigms, which brought significant usability and productivity improvements to consumers; why should factory workers not experience the same? As factory hardware becomes increasingly sophisticated, it’s imperative that HMIs be as intuitive to use as the most popular consumer applications.
I spent years working on various consumer applications in the past, especially games and websites. Since moving to manufacturing, I’ve observed four important ways that UX best practices from consumer applications can be leveraged to greatly improve HMIs for the factories of tomorrow:
1. Maintain visual consistency
One of the most important design principles in consumer UX is consistency. Consistent design elements (whether visual or strictly functional) are intuitive – they eliminate confusion and help users understand how to use your product faster.
Consistency in industrial UX can be even more critical because of the various nuances not present in consumer UX. In these settings, where an array of hardware devices are connected to each other in complex ways, and users range from operators on the factory floor to project managers in remote offices, industrial UX goes far beyond a single screen. Instead, it encompasses the full experience of using the system, including any interface or device that connects to it. It’s a mix of software (dedicated touchscreen panels or apps) and hardware (buttons, feeders) interfaces controlling the machines on the floor, monitors giving real-time status updates about the production line, and services generating reports based on data collected in the cloud over many weeks. Almost every component we build becomes a part of the user experience.
Of course, most design engineers in manufacturing don’t have control over the end-to-end experience given the number of third-party suppliers and integrators used in factory settings. But consistency can still be applied to those interfaces you do control. For example, if you’re designing HMIs for different machines on the line, functionality that is consistent across those machines should look identical. If you’re also designing an interface that shows information about the line as a whole, that should also use consistent visual language – i.e. the same colors and symbols – to represent similar data and concepts.
2. Introduce user testing
Another core principle of UX design is that people form mental models of how a system operates (whether we want them to or not), and if their model sufficiently differs from reality, it will lead to frustration and mistakes. To avoid this and ensure systems are in line with users’ mental models, UX designers conduct user testing – often employing one-on-one interviews. User testing is an essential part of the UX design process that ensures that feedback becomes a core part of the product, making it as intuitive as possible from the very start.
Mental models, of course, aren’t limited to consumers. Factory workers also have preconceived notions of how a system should operate. But in the factory context, user testing for HMI – or, extensive usability testing – is minimal compared to what is done for software or mobile apps. More thorough user testing would be very impactful given the complexity of modern HMIs. As the role of software in manufacturing grows, and more tasks move from hardware to software – whether running on the device itself, in a local server, or in the cloud – the number of ways that factory workers can interact with the system and the complexity of these interactions increases. The next-generation HMIs must be intuitive and straightforward, without being oversimplified. The goal is to design a UX that helps users build the right conceptual models from the start to maximize productivity and minimize training time and mistakes.
Implementing user testing and ensuring that the system operates in accordance with a factory worker’s mental model can help you achieve this goal. Practically speaking, each industry, factory and region may have operators with different mental models, so the challenge is to find a consensus that is usable for most. Even if you’re not set up for formal user research, taking the time to see if an operator on the factory floor can figure out how to do a task with your new HMI without explanation is a great place to start – if they can’t, work to understand why not.
3. Prioritize response time
A few years ago, Google conducted research that found that more than half of mobile website visitors abandon sites that take longer than 3 seconds to load. This 3-second rule has become the de facto standard in the consumer UX world. Page load speeds have become so important to good user experience that UX designers often prioritize response time above all else. While in the consumer world, long loads or slow response times can lead to losing a user or customer, in the factory context, the risk can be more serious. If an HMI is not responsive on the factory floor, it can present a huge safety issue for humans working the line, or cause production issues.
For example, the threshold at which response from the system appears to be instantaneous to the end user is 0.1 seconds – if it takes longer than that for the system to process the user’s input, the system should show that it received the user’s command (a button might change color slightly when pressed, or a transition animation might play). If the system doesn’t respond at all, the operator may think that they didn’t quite press the button, or that something glitched, and might try the button again or even mash it multiple times. If the button is moving a heavy robot arm, redundant commands will make it move in a way the user doesn’t expect and could damage equipment or, in the worst case, even be dangerous to the operator.
At anything greater than a second, a loading spinner or progress bar visual is advised. Folks in factories are more likely to wait it out than a smartphone user, but it’s important to communicate to the operator that the system has received their input and is working on responding if the response is not immediate.
4. Implement common UX guidelines
The ubiquity of thoughtfully designed consumer devices has raised the bar for the quality of user interactions, responsiveness, and clarity in the factory context. Almost every worker in a modern factory has used a smartphone or tablet – this year, global smartphone usage is expected to hit 2.5 billion (and it’s growing). As a result, today’s factory workers have a high level of technical literacy and have come to expect industrial interfaces to work as well as their personal smartphones.
By simply borrowing general design principles from the consumer application world (which were developed through extensive user research), HMI designers can ensure ease of use, and significantly reduce training time for any UX that follows these standards. One example is the idea that users should always know where they are in the UI and how to get back to where they started. A common way to do this when an app or website has a lot of pages in the hierarchy is by using breadcrumbs, but even something as simple as making the navigation bar clean and visible at all times, and highlighting the location or page that the user is currently on, can greatly improve usability.
With advanced technologies like robotics, software and computer vision transforming the manufacturing industry at record speed, the factories of tomorrow demand a more rapid pace of design innovation. By taking a page from the consumer UX playbook, HMI designers can bring more intuitive user experiences to these complex factory environments and help inform the next wave of industrial innovation.
Filed Under: Design World articles, Machine tool industry + subtractive manufacturing, HMIs • operator interfaces • monitors