In the industrial world, poor HMI design can be fatal
Introduction
In the industrial world, HMI design is not just a matter of efficiency — it’s a matter of safety. Industrial User Experience (iUX) exists precisely to ensure that the interface reflects the real state of the machine, avoiding ambiguity, misinterpretation, and, in the worst cases, catastrophic accidents.
B2B vs B2C
Industrial interfaces and B2C interfaces compared
In B2C, design aims to deliver a smooth, pleasant, and engaging experience.
In the industrial B2B sector, that’s not enough: every color, shape, feedback mechanism or command must be verifiable, consistent, and aligned with real processes. Legibility is not optional — it is a safety requirement.
In the industrial environment, the interface must ensure readable safety, guaranteeing that every command, color or signal consistently reflects the machine’s actual state. It is this consistency that prevents disasters — not only in terms of costs, but also in terms of human lives.
A milestone case: Three Mile Island
One of the most cited examples of the importance of HMI design is the Three Mile Island incident (https://www.nrc.gov/docs/ML0402/ML040280573.pdf), widely documented in both official reports and design psychology studies.
The post-incident investigation revealed that the control indicator did not actually show the real state of the valve (PORV) — it only indicated that the solenoid was powered. The operators, therefore, believed the valve was closed when in fact it was open. A complete breakdown of the mental model between human and machine.
As Don Norman — who was involved in the analysis — explained, Three Mile Island was not merely a technical failure, but a design failure: the interface did not speak the operators’ language.
What it teaches iUX
The core principle is clear: in the industrial world, poor HMI design can be fatal.
An Industrial Interface can — and must — be pleasant, clear and intuitive, but never ambiguous. It must reflect the system’s true state, following rigorous standards that define:
• visual hierarchies
• signal priorities
• feedback modalities
• controls and validations
Patterns from the B2C world can be useful, as they speak a familiar language, but they must be adapted, standardized and contextualized to industrial processes.
Only when these requirements are fully met can we focus on aesthetics — not as decoration, but as a consequence of function: beauty that enhances the readability of complexity.
A well-designed iUX
This is the balance the the Digital b.u. of Faentia Group achieves every day: interfaces that put safety first, make processes transparent, and enable operators to communicate correctly with the machine.
Click here to learn more about iUX and how Industrial User Experience can improve human–system interaction.