One of the most important things to consider when designing a human machine interface (HMI) is the user experience. If users are dissatisfied with their experience, they probably won’t be using the HMI very often. This is companies must emphasize the importance of a positive, fluid user interface when designing an HMI. So, how exactly do you achieve a positive user experience with an HMI?
A positive user experience begins with ergonomic controls. Ergonomics, as you may already know, refers to the fitting of a device or workstation to meet the needs of the respective user. An ergonomically designed HMI may feature membrane keys that are soft and contour to the shape of the user’s hand. On the other hand, an HMI with poor ergonomics may feature keys that are either too small, too large and/or placed in awkward locations.
Of course, another element in a positive user experience with HMIs is clarity. The HMI and its respective controls should be clear and easy for the user to see; otherwise, it will create a poor experience that discourages the operator from using the HMI. Using a high-illumination back light will improve an HMI’s clarity. In addition to the right back light, though, an HMI should also be designed with clear controls and keys.
Are users familiar with the HMI and its design? Even if a worker has had no prior experience with the HMI, it should still offer a familiar design. This allows for a seamless transition along with a minimal learning curve. Familiarity is one of the characteristics of a “great interface,” according to an article on Wikipedia.
All HMIs are prone to the occasional error, and that’s okay. However, it should still boast a high level of accuracy to promote a positive user experience. If the HMI has low accuracy and doesn’t respond with the correct output, it creates a poor user experience.
Not surprisingly, responsiveness (or lack thereof) affects the user experience of an HMI. When a user touches an icon or presses a key, he or she expects the HMI to respond in a timely manner. Granted, all HMIs have at least some delay between a command input and output, but if that delay is long it creates a poor user experience. Individuals and companies who design HMIs should focus on a responsive interface in which there’s minimal time delay between command input and output.