The white paper discusses the role of dynamic process simulation for addressing the global shortage of skilled process plant operators.
Industry experts have predicted the upcoming technical labor shortage for years. The process industries are seeing the beginning of the shortage as capital projects worldwide are delayed because companies do not have the engineering staff to execute the projects. However, the worst is yet to come. Refinery operations managers consistently talk about 50 to 70% of their skilled operators retiring in the next 5 years. This shift in skills and knowledge of plant operations staff has incredible implications.
First of all, finding warm bodies (much less experienced operators) to replace all those retirees will become more difficult and more expensive. Process plants must make investments in automation technology in the next several years so that current or greater production can be realized with less plant operations staff. Ideally, the problem of numbers and skills in operations staff could be solved with greater automation investment. But in reality, automation investment alone cannot solve the problem. In addition, the skill of the average plant operator has to increase in order to work with more sophisticated control strategies and manage more automated systems.
Lisanne Bainbridge from the University College London provided valuable insights into operator requirements for automation systems. She summarizes her findings “the more advanced a control system is, so more crucial may be the contribution of the human operator”. Ms. Bainbridge makes several points which warrant examination. Although the paper was published in 1983, it gives insight about how operations managers may deal with the use of automation and the upcoming operator shortage.
The pending crisis in skilled plant operators is compounded by the reality of the three major areas of risk in implementing and managing process automation systems:
- Errors or deficiencies in the automation system application software.
- Inappropriate or insufficient operator actions.
- Errors or deficiencies in the unit operating procedures.
These risks are significant and complicated by loss of experienced operators. However, the use of an off-line simulation system for system testing and operator training can address these risks and mitigate their effects.
Errors in Automation System Application Software
Automation systems are designed and implemented by fallible human beings who make mistakes and have limitations. Ms. Bainbridge points out in her research “that designer errors can be a major source of operating problems.” The sad reality of many automation systems is that the expensive investment is run in manual mode, because the operations staff can run the process better than the system. In fact, most of the focus during a control system selection process is on the vendor or system and network architecture. However, in reality, most modern automation systems provide adequate capabilities for reliable process control. The greatest area of risk is in the application software. The process industry user would be better served by placing more attention on the selection of the designer and integrator of the control strategies.
Demanding that the integrator must use an off-line simulation system for testing the application software also would help the user validate the control strategies, catch automation system design errors, and identify many system integration errors. Automation system design and application software deficiencies can manifest in several areas such as:
- Gross data entry errors.
- Incorrect or inadequate control strategies.
- Poorly designed alarm strategies.
- Operator graphics with too much, not enough or wrong data.
Experienced operators adapt to these deficiencies by taking control strategies to manual or using their knowledge of the process to make control decisions independent of the system. However, a new, inexperienced operator has no ability to adapt. He is much more dependent upon the control system and vulnerable to control system errors. Off-line simulation systems have been proven to be effective tools to test and identify these errors before they affect the operation of the plant.
Inappropriate or Insufficient Operator Actions
Ms. Bainbridge states “the automatic control system has been put in because it can do the job better than the operator, but yet the operator is being asked to monitor that it is working effectively.” The operator in an automated process plant must be more knowledgeable and effective than the control system because the operator role is a supervisor to the automation system. ; This puts incredible responsibility on the operator to “monitor the computer’s decisions at some meta-level, to decide whether the computer’s decisions are acceptable.” Newer operating units are generally more stable by design. In these units, the operations staff may go months or years without having to take preventative or correction action to avoid an incident. Operators can easily loose critical skills and knowledge required to respond.
Off-line simulation systems provide a safe and effective environment to train operator actions and responses during normal and upset process conditions. They have been used to increase the skills of new operators and reinforce the capabilities of experienced operators. The simulation system should be used to ensure:
- Operator actions are appropriate in both the type of actions and the magnitude of the actions. The ability of an experienced operator to smoothly respond to changing conditions with setpoint or load changes can be taught and verified in an off-line simulation system.
- Operator actions are sufficient. Operations staff can be taught how to respond to different process upsets and how to interpret data from the off-line simulation system so sufficient operation changes can be made in the on-line automation system.
Operator training using an off-line simulation system should be an integral part of the new unit commissioning and also ongoing operational excellence initiatives. Ms. Bainbridge states that “the most successful automated systems, with rare need for manual intervention, may need the greatest investment in human operator training.” As new operators are hired or experienced ones retire, the off-line simulation system will provide significant returns in the operations of the process plant.
Errors in Unit Operating Procedures
Too much credibility and not enough effort are put into unit operating procedures. As new operators are hired, unit operating procedures are the first point of training. In many plants, a review of the operating procedures is the only form of operator training outside of on-the-job live process operations. This can pose a great risk to the operations of the plant due to following:
- Errors in unit operating procedures are not addressed resulting in experienced operators straying from the documented procedures.
- Deficiencies in the unit operating procedures to address real process upsets result in experienced operators developing informal and undocumented procedures for addressing these conditions.
While experienced operators can overcome errors and deficiencies in unit operating procedures by their experience and stored knowledge, new operators are much more dependent upon these procedures to monitor and control the plant. In some cases the issue is the manner in which the operating procedures are written and managed. However, Ms. Bainbridge states, “It is inadequate to expect the operator to react to unfamiliar events solely by consulting operating procedures.” The use of the off-line simulation system has been proven effective to:
- Test and develop accurate and sufficient unit operating procedures. The simulation system and experienced operators can be used to develop knowledge transfer from retiring operators to the next generation.
- Train process operations staff on the operation of the process using the unit operating procedures.
Although, unit operations procedures are an essential part of operator training, they are not the complete answer. In addition, the use of the off-line simulation system will allow operators to develop the necessary skills to safely and effectively manage the automation system and the process plant.
Simulation Systems Requirements
The use of an off-line simulation system should be an integral part of every process plants strategy to deal with the upcoming operator shortage crisis. However, not all simulation systems can be used to address the necessary tasks and requirements. Simulation systems for testing automation system application software and unit operating procedures, and training operators need to meet the following requirements.
It must protect the automation system integrity. The simulation system must be non-intrusive to the off-line process automation system. This requires the simulation system to read and write to IO values, making the automation system react to realistic process signals in a normal manner. The simulator must work without modification to the automation system environment so that the application software in the off-line system is identical to the operating system. Finally, the simulator should integrate with the off-line automation system automatically.
- It must allow selective application of accurate, dynamic modeling per unit operation. In order to manage simulation development costs and time, models should be developed to meet the needs of the testing or training task. The automation and operation of a tank farm can be simulated with a much simpler model than a distillation column. As a general rule, the simpler the simulation, the easier to develop and maintain.
- It must be designed for automation system software acceptance testing and operator training.; Simulation systems designed for these functions can be used by automation system integrators or operations staff without extensive simulation training. For testing, the system must be flexible and allow the user to view his simulated values easily, dynamically, and in a flexible manner. For training, the system should allow the development of structured operator training sessions and scenarios with tools to evaluate operator skills and responses.
The upcoming operator shortage crisis will affect all users in the process industries. Forward-thinking operations managers will incorporate off-line simulation systems as a method to address this crisis and ensure a stable and safe plant environment in the future.
