John Krajewski has recently published a white paper on “Situational Awareness: The Next Leap
in Industrial Human Machine Interface Design". This blog post reviews the
industrial operators interface evolution and covers his findings on the trends that
currently drive the needs of the industrial HMI application.
An Illustration of Industrial Operator Interface Evolution
“Over
the past several decades the way people have interacted with industrial systems
has changed dramatically as depicted in Figure below. These changes were driven
by the needs of the operations staff to improve the way that they use, manage,
and maintain those systems coupled with advances in technology that facilitated
those improvements. Changes like this will continue to naturally occur over the
coming decades and will be driven by market needs coupled with advances in
technology that address those needs and provide further opportunities for
improvements. There are several trends in the current implementations of
industrial automation human machine interface (HMI) systems that are driven by
the current market needs. The trends that are currently driving the needs of
industrial HMI application design are
larger systems, greater volumes of data, increased levels of automation,
staffing proficiency issues, and expanded use of remote operations. Each of
these industry trends poses new challenges that can severely impact the ability
for an operations team to achieve optimal business performance of their systems
and safe operations.
Larger
Systems and the Increased Span of Control
The
number of pieces of equipment used in modern industrial systems is continuing
to grow as the cost of connected devices continues to fall, the capabilities of
control systems to handle more equipment rises, the reliability and bandwidth of
networks grows, and the demands of industrial systems are driven by the
business needs of larger global markets. While the technology has enabled more
and more pieces of equipment to be connected into an integrated system, the
user interfaces into these systems have not evolved at the same pace to
effectively handle this increase. Modern operations teams are using fewer
resources to staff these systems and the span of control of an operator is growing
while the techniques he utilizes to manage his system were not designed for
such volumes of equipment.
Another
key factor in the growth of systems has been the integration of much larger
geographic areas into single systems than was possible or practical in the
past. These larger systems allow users to make key operational decisions in
real time, such as determining which production facility can produce a service
or product at the least cost. The costs and reliability of networking such
systems together continues to improve and in result these types of systems are
commonplace today. Whatever the business driver, the end result of these larger
systems is an overload of the operator with much greater volumes of data than
they can effectively manage.
Greater
Volumes of Data and the Increased Operator Load
Even
as the number of pieces of equipment grows, the equipment itself is generating
more data. In the past, a single transmitter may have generated only a single
value connected into the monitoring system, but modern transmitters have
additional diagnostics, onboard control, and many tuning parameters all of
which have increased the data density per piece of equipment by multiple orders
of magnitude. In many cases the user interfaces that contain this data have not
been designed to optimize the operator interpretation of this data and further
compounds the operator overload described in the previous section.
Increased
Levels of Automation and the Unintended Consequences
In
an effort to reduce the variability that human operators can introduce, more
and more of the functions performed in industrial automation systems are
automated by control loops and process sequences. These control loops and process
sequences do offer the operator some relief from the factors already discussed
that increase their workload but also have unintended side effects. As the
operations teams are rarely involved in the design and implementation of such
systems they have little understanding of the actions being taken by the
control system and they become disconnected from the process. This can lead to
an over-dependency on the system to drive operator behaviors through mechanisms
like alarms or process interlocks. It is very common to hear that operations
teams are reduced to either resolving interlocks or reacting to process alarms.
In this type of environment the operator is performing reactively and cannot
prevent disruptions but instead can only react too them when they occur.
Staffing
Issues and the Impact on Proficiency
As
these systems evolve, and the user interface design techniques are kept mostly
the same as has been done prior to these evolutions, it has driven up the
amount of time that it takes to bring a new resource on board and make them proficient
in utilizing these systems. It is common to hear that it will take about 2 years
for an operator to become proficient on a system. This extended period of time
is required because the operators need to become experts on the system to make
up for deficiencies in the system design. However, other conditions in the
market are shortening the length of employment terms. Operations staff have
more freedom to seek employment elsewhere, advance through
their
organizations and a variety of other causes that result in the average term of
employment being near 2 years. This means that the operations teams are rarely
at maximum proficiency. Another common concern in nearly every market is the
impending retirement of the people who best understand the systems and the need
to replace these experts and bring those replacements up to speed quickly.
Something must be done to reduce the amount of time taken to achieve both
operator proficiency and the variability in the quality of the process from one
resource to another.
Remote
Operations and the Challenge of Distance
With
advances in networking technologies and reduction in costs for these
technologies it is becoming more commonplace to remove the operator from the
location where the process is actually taking place. This can often be driven
by needs such as safety, optimizing staff utilization through increased span of
control, or a need to locate the operations where subject matter experts are
available. Whatever the reasoning, this separation is presenting further
challenges to the operations teams as they can no longer employ the same number
of senses as they could when they were located near the actual equipment. Many
operators have described being able to understand the equipment and process
status through sensing sounds, vibrations and smells alone. When the operations
are remote and these additional senses are no longer able to be used, the
operations team becomes even more dependent on
the
effectiveness of the HMI in communicating the state of the system or process.
But too often the user interface has been implemented by recreating and
animating the Piping and Instrumentation Diagrams (P&ID). But these
P&ID’s were never designed to overcome these challenges and as such this
results in operators that poorly understand their systems and how to properly
manage them.”
Krajewski,
John (“Situational Awareness The
Next Leap in Industrial Human Machine Interface Design”
Which of these trends are you experiencing in your facility? Let me know in the Comments section below
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