I'm looking to collect input on best practices for the design of industrial HMI.

There are already standards promoted such as ISA-5.5-1985, Graphic Symbols for Process Displays, but the writing mainly focuses on representing a P&ID (Piping and instrumentation diagram) on a computer terminal. This doesn't really address questions regarding putting items on the interface that a user will use to control process flow.

An example user interface is provided (critiques welcome): Generic Control Screen for a Hydroelectric Turbine

4 Answers 4


@Greg, I've worked in electricity power distribution monitoring, but it was monitoring and not control, so I know nothing of standards or indeed best practice in your area - what I have to say here is impressions as an informed but not expert reviewer.

  • Having controls around the edge of the panel is good (Fitts law). If the 'Stop' control is like an emergency shutdown it should be larger than the start control. I would look at using more space for all the controls. I am assuming this as being for use both on touch screen and not.
  • What color do you use to indicate problem? At the moment you are using red for closed and off, are those actually problems that an operator needs to be alerted to in this image? Would a neutral gray be better if it is just a perfectly OK operational state?
  • Context. It would be an improvement to show a thumbnail overview of the plant, or relevant area of plant, inset at bottom right, with this unit highlighted. You can afford to reduce the size of the diagram for this unit a bit to help make the space.

History - should there be some indication of recent operational status, e.g. duration of operation? On the motor protection controllers I worked on the number of recent restart attempts was vital information.

Communication Status - how is communication status shown? Here we know that the cooling water valve is open. How do we know when communication with the valve is lost and we are guessing based on last known state?

  • I appreciate the input! Based on your comment I am evaluating specifying that "safe" operation commands like "Stop" are moved to the edge of the screen. Emergency-Stop isn't really a problem as there are physical pushbuttons both at the operator control area as well as on the production floor. Colors change depending on context, but I agree with your sentiments about only indicating color for alert states. Green on mechanical indicates operation, Green on electrical means non-powered. Communication status is indicated both by an alarm log, as well as by Black text on Megenta background. May 25, 2011 at 2:50

I sadly don't think there is one standard you can follow for every site, and I can't even think of many best practices as they change per site and HMI software bundle. For example I could say you should have red for running and green for stopped and neither of us would be wrong. That stuffs always up to the customer, and they are determined to make it the opposite of whatever you last worked on.

Also I think your screen is pretty busy, I'd recommend removing half the stuff in your factory. If that for some reason isn't an option you could clean up the navigation bar at the bottom by segmenting the site, big sites having a bread crumb trail, small stuff (less than ~10 mimics) like touch screens just showing the button to navigate to the current screen in a different color.

  • How's "red for running and green for stopped" a convention? Red has always been associate with danger and problems while green has meant "all's good".
    – dnbrv
    Feb 27, 2012 at 23:21
  • If you have a motor that is running its dangerous - red. and when you have a motor that is in a condition that is all good to start, it's green. I didn't make this up, unlike red traffic lights meaning go in China, which the red guard did make up... but I think they have stopped that now thankfully.
    – daniel
    Feb 28, 2012 at 0:04
  • If the purpose of the engine to run, then when it's off, it should be black or something neutral.
    – dnbrv
    Feb 28, 2012 at 0:25
  • Yea, the most common I have seen is grey for not running, flashing yellow on top for faulted. Then red (or green) on that for running. But what happens if they have a black background and you chose black motors, I had a screen once that had black buttons with no borders on a black screen, the operators hated it.
    – daniel
    Feb 28, 2012 at 0:40
  • Well, yeah. If there's no contrast with the background, it won't work. My point is that red for something that operates within the designed limits isn't common or universally understood.
    – dnbrv
    Feb 28, 2012 at 0:47

There's been quite a lot of research into Control Room design over the years.



The more 'physical' control rooms of the past need to map smoothly onto screenbased designs.

  • Could you summarise the contents of that article?
    – Rahul
    Feb 28, 2012 at 16:13

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