In this video,
we are going to discuss “High-Performance HMI”.
“High-Performance HMI” is the industry answer for a standardized, easy to use,
and more productive HMI graphics system to implement
and in some cases, replace a poorly designed HMI.
As we know, operator control of processes
is done using a graphical representation of the process,
known as an HMI, or “Human Machine Interface”.
A properly designed HMI will support a smooth and stable operation of the process
as well as notify the operator of an abnormal condition.
However, this isn’t always the case.
Many HMIs were poorly designed and implemented,
leading to situations that can compromise safety, quality, and profitability.
Many current HMIs make use of a broad spectrum of colors,
unnecessary graphics, visual distractions
and lack of overall situational awareness.
These, in turn, can result in negative consequences.
Some of these consequences can include poor operating procedures,
such as “running by the alarms”,
where an operator is only responding to alarms
and not understanding the root cause of the alarm conditions.
In other cases, a poorly designed HMI will result in avoidable upsets
and increase the likelihood of less than the optimum response to an abnormal situation.
In the worst cases,
a poorly designed HMI has been identified as a contributing factor
in some industrial accidents.
Let’s talk about how we got here.
Early HMIs were simple depictions of the “P&ID”
of the process that they were controlling and monitoring.
This was mostly from the limitations of the computing
and graphics power of the times.
As computing power and graphics processors advanced,
so did the mindset that a highly complex,
data filled and visually striking HMI should follow.
We see flickering flames to represent a flare,
moving rail cars in loading bays,
some have gone as far as to take digital photos of the actual process floor
and overlay data on the HMI screens!
Add this mindset to the thousands of systems integrators,
and what we have ended up with is an industry that has no standard displays,
even identical processes can have vastly different HMI screens,
depending on who implemented them
and what the customer thought that they wanted.
There are HMIs all around the world with inconsistent navigation,
difficult to understand data being presented,
improper alarm depictions and a lack of display methodologies
presenting the state of the operating equipment.
Let's move away from these HMIs and learn about the High-Performance HMI.
In 2003, the “International Society of Automation” or “ISA”,
tasked a group of end users, operators, and engineers
to start working on a standard.
In 2015, twelve years later,
they published the “ISA101 HMI Design Standard”.
It is the set of guidelines, principles, and philosophies
for developing graphics on a process HMI.
This standard is meant to create a more functional,
easy to understand, and information-driven operator interface.
Here we are going to cover the basic concepts of High-Performance HMI.
One concept is the proper use of color.
Moving away from the intense and colorful graphics,
the High-Performance HMI is developed in grayscale,
with color intended to be the attention getter.
Gone are the days of red and green to indicate running or not running.
In a grayscale screen,
the use of color is meant to indicate an abnormal situation very quickly.
It has been shown that the new use of color alone
has resulted in a 48% improvement in detecting abnormal situations before alarms occur.
A grayscale screen with no color present
means a normal operating plant with no alarms.
A quick glance by an operator can confirm this
and productivity can increase as the operators do not have to spend time
studying a screen to look for abnormal situations.
Another concept is the use of information over data.
Many HMIs will have dozens or more data points visible on the screen,
but nothing for an operator to determine what that data means.
A pressure indicator could read 900 psi,
but is that a good thing or a bad thing?
By utilizing an indicator of normal range with a process variable,
the operator can make a quick decision
to take action to correct a situation that is trending away from normal.
Speaking of trends, we now are seeing embedded
or always visible trends on important process variables.
By making these trends always visible,
the operator can see a quick overview of historical data
and evaluate for any necessary process adjustments
before a product runs out of specification or a tank overflows,
both time consuming and costly mistakes that can now be avoided.
A very important concept in High-Performance HMI
is keeping the screen simple and uncluttered.
A simple depiction of a vessel with a valve and pump is all that is necessary.
Along with that are easy to find navigation buttons
that will take the operator to the next step in the overall process.
There is no need to show bulkhead fittings, flanges,
or non essential 3D pipe objects.
Instead, an ISA standard valve and pump,
using a line to depict process flow are the standard.
When depicting the status of a pump or valve,
instead of red and green for running or not running on a pump
or open and closed on a valve,
High-Performance HMI will use a dark gray status for a pump that is stopped
and white for a pump that is running.
For a pump that does not send feedback to SCADA,
it will be depicted as medium gray.
Proper display hierarchy is critical to a High-Performance HMI.
By creating a hierarchical system of displays,
the operators can have overall situational awareness,
and the ability to drill down to very specific data points when necessary.
There are four levels of hierarchy in the High-Performance HMI.
Level 1 is used for overall situational awareness.
An operator can see the entire process at a very high level from this screen.
Level 2 is a screen that an operator can access to view a smaller
and more detailed view than Level 1.
Level 2 will call a sub system or process in greater detail than Level 1.
Level 3 is the equipment details screen, such as a pump or a valve.
It will include even more detailed data on that particular process.
Finally, Level 4 is the diagnostics screen.
This will give the operator access to very detailed information on a process device
and is accessed for troubleshooting purposes.
High-Performance HMI is still a moving target
and is still subject to the preferences of the stakeholders.
However, it has been shown that when presented with the concepts of High-Performance HMI,
operators are eager and excited to implement it into their system.
While all systems are different,
utilizing a more standardized model
will vastly improve productivity, quality, and safety.
Some of the graphics and the HMI screens used in this video
are from the High-Performance HMI handbook
which is a great reference if you want to dig deeper into this topic.
You can find the link to the book in the description below.
Thank you for watching this video,
and be sure to look for Part 2,
“Fundamentals of High-Performance HMI design”.
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