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 OTS.
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 process models
- 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 console
- Ability to run exercises without an instructor
- Maintained to remain consistent with the actual process and controls.
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 components.
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 startup
- 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 days.
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 categories:
- Reduced in planned turnaround time
- Fewer in abnormal situations or incidents caused by human error
- 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 turnaround time.
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 annual budget.
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 quantifiable categories:
- Initial startup savings of eight days
- One saved day on subsequent startups on overall turnaround
- 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 period.3
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 stated:2
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 quantify.
Using very conservative estimation methods, the estimated benefits for OTSs show a return on investment certain to surpass the typical corporate investment hurdle rate. HP
1 French, S. J. , Phillips 66 Co.s financial benefits road map using Honeywell Hi Spec dynamic training simulator, NPRA Computer Conference, October 2001.
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.
||Tom 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. |
||Peter de 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. |