In the airline industry, pilots are responsible for complex
and expensive equipment, and the lives of many people. Flight
simulators are used to train pilots for nontypical events, such
as engine failure and water landing, and pilots are required to
spend a specified amount of time per quarter-year in simulator
training, to maintain certification.
As the role of the process console operator has evolved, and
he or she now controls more pieces of equipment (assets) and
more control loops. The process console operator role
approaches the responsibility of a pilot with similar levels of
consequences when a failure occurs. Many progressive processing
companies have installed operator training simulators (OTSs) to
train operators for both routine operations (startup and
shutdown) and abnormal situations.
Many processing plant executives want to know the financial
benefits and justification for implementing and maintaining
OTSs for their existing plants and several examples quantify
those benefits. However, before discussing the benefits of the
process, it is important to understand the components of an
The components of a first-class OTS include:
- Same equipment, distributed control system configuration,
tags and logic as the actual plant
- Training environment nearly identical to
the control room
- High level of realism due to reasonably accurate dynamic
- Realistic process models to provide the sense for urgency
in reacting to training exercise events
- Used in teaching operators to recognize and react to
plant-specific events and scenarios, with an instructor
- Ability to run exercises without an instructor
- Maintained to remain consistent with the actual process
Fig. 1 is a diagram containing these
components. Fig. 2 illustrates a typical OTS
graphic, while Fig. 3 offers an example of a
typical OTS training room.
Fig. 1. OTS
Fig. 2. A
typical OTS graphic.
Fig. 3. Two engineers
train in an OTS control room.
Costs. An OTS for a standard refinery process unit, like a fluid
catalytic cracking unit, including the various software,
hardware and service components, will cost approximately
$700,000 or more, depending on overall complexity of the unit
and the type of control integration that is required. In the
presented example, we will assume a cost of $7 million to cover
the expense of multiple OTSs for different processing units,
not to mention costs associated with training, hardware, maintenance and support.
Benefits. Today, construction projects for most new process units
include an OTS. The financial benefits alone for an OTS in
greenfield plants have been well documented for more than a
decade. When itemizing the usefulness of an OTS, one cannot
overlook that it offers:1
- Excellent startup training
- Ability to review written operating procedures prior to
- Identification of major process/logic/control limitations
before unit startup
- Ability to demonstrate control applications before
deployment to the plant
- Reduction of the initial startup period by several
It is also clear that OTSs generate significant benefits for
brownfield units (or through the entire lifecycle of a process
unit). Several brownfield clients have had OTS programs in
operation for all of their plants process units for over
20 years. These companies continue to maintain and update their
OTSs, ensuring that the OTSs are an integral part of their
plants continuing operator training.
The main economic benefits of an OTS fall into four
- Reduced in planned turnaround time
- Fewer in abnormal situations or incidents caused by human
- Improved advanced process control (ARC) utilization
- Less in capital equipment for repairs.
Some additional benefits are smaller or may be more
difficult to quantify. These include benefits resulting from
safety improvements, fewer environmental incidents, increased
mechanical integrity and energy savings (resulting from fewer
startups and shutdowns). The additional benefits, which can be
significant, are not estimated here.
The total annualized benefits from an OTS for a 100,000-bpd
refinery are estimated and
summarized in Table 1.
One of the key benefits that OTSs offer is a reduction in
planned turnaround time. This benefit includes planned startup
and shutdown time before and after scheduled maintenance. It is
not intended to include benefits for unplanned shutdowns and maintenance. As described in a
previous article, an operating company used a basis of 10%
reduction in startup time from using a simulator for a
brownfield unit.2 We will extend this to include a
5% reduction in shutdown time and an additional 5% for better
operator understanding, for a total of 20% reduction in
Using a cracked spread of $24/bbl and a charge rate of
100,000 bpd, this provides a profit of $2.4 million/day. With a
conservative 14-day turnaround every three years, an OTS is
estimated to generate an annual benefit of $2.24 million.
OTS are also useful when addressing the reduction in
abnormal situations or incidents caused by human error. An
operating company used the following as a basis to estimate the
benefits of an OTS:2
- Half of the incidents that were either caused by or
exacerbated by human error will be eliminated
- A quarter of the incidents that may have been exacerbated
by human error will be eliminated
- The benefit for a refinery should therefore be calculated
to be a reduction in plant downtime of 15%.
Using the previously calculated daily profit of $2.4
million/day, and four days per year for unplanned downtime, a
15% reduction in downtime yields a conservative OTS annual
benefit of $1.44 million.
APC utilization can also be optimitized. This benefit is
estimated as a 15% improvement in total plant APC benefits
because operators understand and utilize the APC better, and
therefore have higher utilization factors. A conservative $7.4
million in annual APC benefits was used here, generated using a
simple refinery APC payback calculation to estimate a 15%
improvement of $1.11 million/yr.
One should also not forget that an OTS offers a reduction in
capital equipment for repairs. When abnormal incidents occur
due to human error, equipment and materials are required for
repairs or additional wear-out because of the incident. This
estimate attempts to quantify those preventable costs. The
benefit is calculated by a reduction in the plants
capital budget of 0.5% in total material costs of a $22 million
These benefit estimates are based upon a generic refinery configuration and size.
Heuristics, experience, simple financial models and engineering
judgments were used for the calculation of these benefits. A
better estimate for an actual process could be generated by
looking at five years of incident data on a unit-by-unit basis,
with actual margins and process unit rates.
The annual benefit estimated would provide a simple pay-out
time of less than two years, even when the cost of simulator maintenance and instructor costs are
added. This should easily surpass the investment hurdle rate of
most processing companies.
BP Chemical previously studied OTS benefits.3 In
a five-year period, BP installed OTSs at four of its major
chemical sites in the UK. Benefits were estimated from four
- Initial startup savings of eight days
- One saved day on subsequent startups on overall
- Two production days saved each year from improved
recovery from upsets
- One percent improvement in costs through better control
of the plant.
These benefits are in line with the benefits estimates
provided in Table 1. In addition, at another
site, BP reported a benefit that was 20 times simple payback
over the original investment in a five-year
The beneficial nature of OTSs has been quantified here using
experience, simple financial models, good engineering judgment
and financial calculations. As two of our colleagues
The justification for an OTS in a greenfield project is more obvious than for an
existing plant. In a new plant, operators need to be trained on
something that does not yet exist, whereas the direct benefit
of an OTS for training in an existing plant is less certain.
Even so, most agree that such a training system in existing
plants can reduce losses by improving the startup time, prevent
unscheduled downtime and equipment repairs, and maintain
production throughputs. It is, however hard to
Using very conservative estimation methods, the estimated
benefits for OTSs show a return on investment certain to
surpass the typical corporate investment hurdle rate.
1 French, S. J. , Phillips 66 Co.s
financial benefits road map using Honeywell Hi Spec dynamic
training simulator, NPRA Computer Conference, October
2 Mason, J. and J. A. Alamo, The role of OTS
in operator training programs, Control
Engineering, Nov. 2, 2010.
3 Fiske, T., Uses and benefits of dynamic
simulation for operator training systems, ARC
Insights, August 9, 2007.
Ayral works for Honeywells Advanced
Solutions division. He has over 30 years of experience
bringing new technology to the oil and
chemical industries. Mr. Ayral has a BS degree in
chemical engineering and an MBA degree. He specializes
in developing economic justifications of technologies
and has published over 80 articles.
Jonge graduated with a BSc degree in chemical
engineering from the University of New Brunswick in
Canada. Mr. de Jonge joined Honeywell as an application
engineer for UniSim Design. In March 2008, he
transitioned into his current role as a simulation
business consultant. He is a registered professional
engineer in Alberta, Canada.