Human Factors

Why should we upgrade the control system's user interface?

When upgrading your legacy system, don't underestimate the importance of upgrading the user interface of the control system, use it as an opportunity.

Nearly 50 years have passed since operation by computer graphics made its way into control rooms. The early simple pixel-based graphics with very limited design possibilities are in great contrast to today's systems with vector-based graphics and almost unlimited possibilities. Vendors use their updated HMI capabilities when they sell upgrades and migration from legacy to new versions, but we rarely see any real update of the user interface. Why is that?



Upgrading legacy systems

For most upgrades of legacy systems, the quick fix is to do a 1:1 conversion of the displays - copy and paste, add some of the new system functionalities. The old saying "don't fix it if it ain't broken" has saved many a project manager both time and expenses. But is this entirely true? Is it true that an interface originally developed in the 1990s will work just as well in 2022 (even with some superficial "make-up")? Could there be a bigger savings potential by upgrading in a more thorough way?


We completely understand that no one would be comfortable working with a 2022 state-of-the-art laptop that still uses Windows 95 as its user interface. So why should your control room operator have to stick with it after system upgrades worth millions in hardware and software?


However, it's a fact that many companies neglect the importance of upgrading the operator's daily tool: the graphic displays - the user interface. Over the years, and after upgrades and modifications, the user interface has changed only marginally, and still reflects the 1980s or 90s design, not utilising new technology and considerably better quality and specifications for both software and hardware.


Changes in Graphic User Interface

While some human factor and user interface principles may not have changed much in the last 40-50 years, it has been a huge progress in the graphic user interface area, and most of the improvements are solidly based on human factors and UI principles. A lot of research and development have had big impact on human centred design, including icons and symbols, navigation and hierarchy concepts, use of colour and design of user dialogues.


  • When the time has come to upgrade your legacy system, don't underestimate the importance of upgrading the user interface. Instead of going the quick and dirty 1:1 route, use this opportunity to improve the user interface of the control system. Look for areas of improvement, make use of new functionality to give your operators a better and more effective tool.


How can we successfully complete the upgrades?

There are many means to this end, and also differences in what is regarded as "user friendly graphics and operations". As a starting point, the EEMUA 201 guideline give some useful advice on how to handle upgrade projects as well as new projects.


Here are some areas that should be considered in any system upgrade:

  • Develop an HMI or UI guideline if it's not already in place. If you have one, make sure it's updated in line with new functionalities and possibilities in the control system.
  • Upgrade the alarm system. This is often as outdated as the graphic displays and is a major cause for high workload and stress for the operators. If you don't have an alarm philosophy, make sure you develop one. Eldor's template can be used for this purpose.
  • Involve the operators and end users, challenge them on their use of displays, brainstorm and re-develop task-based HMI that are founded on actual tasks, the operator's experience, and possibilities in the system.
  • Collaborate with the system vendor, ensure that the new HMI is tidy and not burdened with "old sins". Validate and verify in a test-system, not only on paper.

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