High Performance HMIs: Is Everything I Know Wrong?
By Nicholas Imfeld on January 18, 2012.
I’ve recently been reading a book entitled The High Performance HMI Handbook. Our Director of Engineering requested that I tackle this one and report back. As an integration services company that has developed hundreds of HMI applications of various shapes, sizes, complexity, and industries, we are always on the lookout for new concepts and ideas that we can implement to make our customer’s HMIs better. We want to be continually improving our practices and standards (after all, as a previous post said, our industry is always advancing, and so must our standards). So my mission is to read this book and see what we could learn and apply.
I’ll be honest, when I first started, I wasn’t expecting a whole lot. And it didn’t help that the introductory chapters were pretty heavy-handed that conventional wisdom when it comes to HMI development was incorrect. I’ve been doing HMI development for over ten years now; certainly I’ve learned a thing or two in that time. Who were these guys to write a book telling us we’ve been doing it all wrong for decades and then charge us a hefty sum to read it? And you wouldn’t believe the derision they heaped on the conventional HMI screen that was nothing more than P&ID with “live values ‘sprinkled’ all over it” (I’ve seen a lot of HMIs that meet this description). But still I pressed on…
My interest was piqued when the authors began to describe the evolution of how the industry arrived at the current “state-of-the-art”. Originally process visualization consisted of massive walls full of instruments and charts and digital indicators (there are likely some readers who remember these walls, but that was before my time). Even though I’m sure that all of the spaghetti behind the wall was a nightmare to troubleshoot and maintain, the degree of visibility into the process had to be amazing. With one glance, you could see everything you needed to see. What a downgrade it must have been to move from a wall that stretched from one end of the room to another to a tiny monochromatic screen that only showed a handful of the elements contained by your process. Obviously, these new screens cut down much of the wiring that was required for the visualization wall, but now we’re left trying to control our process through a peephole. And apparently, we’ve spent the subsequent decades with limited success trying to take advantage of improved technology to expand our peephole back the level of visibility we once had. For more on the history of that process you’ll have to check out the book because reviewing it is not my purpose here. What I really want to do is to introduce some of the concepts the book talked about next.
After their brief history of the HMI they transitioned into discussion of how to develop a “High Performance HMI”. The “High Performance HMI” is developed using techniques that when rightly utilized give you that wide view of your process that the average HMI is often lacking. As I said before, I was skeptical. I didn’t think they’d have anything dramatically different to offer. I was pleasantly surprised. So I’d like to take a few blog posts and share with you a few of their ideas that we can incorporate into our standards (and your HMIs) that could really go a long way towards making them cleaner, clearer, and more useful. So check back in. Here is what you have to look forward to:
Building a Better Bar Graph: What an Analog can tell you with just a glance
The Hip New Trends: No longer a screen no one looks at
Overcast Graphics: Why grayer is better
And finally, I’ll end with one more post:
What it all means for us and what it all means for you.