New graphics technologies give us some really stunning images of systems running on an HMI, and they look very cool.
Nowadays we can virtually “see” tanks and watch them fill in blue corresponding to water level; we can even “see” rotating agitators. It’s almost like physically watching the equipment run, and we can do so from any remote HMI terminal that has access. We can add pumps that look like they’re spinning when they turn on and make the pipes turn colors to simulate fluid flow so we can pretend we’re actually watching what’s going on inside of them.
But is that really useful?
Over the past few years, a less flashy method of “High Performance HMI” development has been catching on, and for good reason. The simple goal of an HMI is to give operators a tool to perform their duties as effectively as possible: in other words, having a bunch of really cool graphics is not always a good thing. Companies all over the globe are rallying around the original that an HMI should only display what is important.
Take a look at the images above. Both depict similar processes, but the simpler one on the right immediately shows the operator whether or not the system is running as it should. The one on the left does not. The fancy graphics actually make it harder for operators to analyze the system. They’re pretty, but they get in the way.
As reported in a Rockwell presentation entitled The High Performance HMI: Proper Graphics for Operator Effectiveness, High Performance HMIs improve an operator’s ability to detect abnormal situations by a factor of 500%. They give operators a 37% better success rate over poorly designed HMIs in handling abnormal situations, and a 41% reduction in the time it takes to complete abnormal tasks they have identified.
In short, the next time you have to create an HMI, at least propose the idea for them to accept the new High Performance HMI approach. Operators will usually hate it at first, but learn to like it once they are used to it.