May/June 2011

Automate to retain knowledge, ensure safer plants

By Ellen Fussell Policastro

When human beings work in the process industries, there is bound to be some variability in the way they handle certain processes. When an inexperienced operator has to start a unit or furnace, and processes are out of sequence, it could result in a dangerous situation or even a fatal explosion.

Automating these processes to alleviate human error is what ISA106, Procedural Automation for Continuous Process Operations, is all about. Available and repeatable procedures can lower the chances of accidents due to human error. Beyond helping alleviate potential disaster, some of the benefits of automating process operations include helping companies retain skills, manage knowledge, reduce variability, reduce risk to the facility, and increase productivity.

Manage, retain knowledge

An ever-changing workforce in which retirees are handing over the reins to less experienced operators has begun to hit process manufacturers around the world. The aging workforce also means a loss of operational skills and knowledge. Keeping this knowledge intact for future workers, also known as tribal-knowledge retention, is critical to ensuring the integrity of procedures. "Retaining this knowledge in automated procedures is most important with procedures that aren't required so frequently," said Maurice Wilkins, vice-president at Yokogawa in Carrollton, Tex., and managing director of ISA106. "Once the knowledge has been properly captured into an optimized procedure, the procedures can be used as the base material for training new operators on that particular process. If those procedures not only explain the 'what' but also the 'why,' they will enable new operator understanding in record time," he said.

"One plant reported problems with a turnaround in which existing operators lacked sufficient experience to restart the plant," Wilkins said. "The company brought in retired operators with experience to start up the process safely and efficiently. If this process had been automated, they would have had a systematic approach to capture valuable skills before they walked out the door."

Reducing variability within processes also means products are more consistently built within specifications. This leads to the potential for more refined procedures. It also means these procedures are available 24/7 to all operational teams and operator skill levels.

New document in the works

The committee is now working on its first technical report targeted at oil refineries, upstream offshore oil rigs, and chemical plants, all of which deal with continuous processes. "Companies such as Dow Chemical, Chevron, ConocoPhillips, and Shell, are involved with the ISA106 effort because of their concern from a safety regulation standpoint as well as their desire to increase efficiency," said ISA106 Co-chairman Yahya Nazer, associate consultant at Dow Chemical in Lake Jackson, Tex. The technical report will deal with models and terminology, "so end users can have a common set of terms with uniform definitions to describe the requirements in improvements, upgrades, and changes in procedural automation to system integrators and automation suppliers." A few other topics planned for the technical report include modularizing procedural steps, exception handling for abnormal situations, state mode procedural logic, process unit orientation, and current practices.

"The goal of the planned ISA-106 series of documents is to help users standardize their designs to handle operator errors in normal, critical, and abnormal situations," said Dave Emerson, director at Yokogawa in Carrollton, Tex., and vice-chairman of the ISA106 committee. "A standard approach to those situations will help end users recover from those errors and more quickly return to a normal situation."

The ISA-106 document series will describe how to minimize startup and shutdown times and reduce unnecessary alarms during automated procedures. "Users will be able to efficiently manage their alarm handling by using automated procedures to address alarm conditions. 

Fewer shutdowns

Equipment transitions are also a major cause of disturbance in continuous processes. "Whether they are required for preventive maintenance (such as pump swapping), to address performance degradation, or simply during calibration, these events qualify as abnormal production conditions and will affect production rates," said ISA106 Co-chair Marty King, technical team lead at Chevron Energy Technology Company. "Efficient, planned, and automated procedures will ensure plants can maintain maximum production rates, minimize recovery time, and avoid unintended shutdowns."

Users have also experienced inefficient transitions from one situation to nominal production following changes in a process. Some examples include raw material grade change, finished and intermediate product specification change, and throughput changes. "A planned transition recovery is much faster than restarting a production line from a complete shutdown, and most often the temporary production output can still qualify as a product of maybe a lower grade," King said. "The ISA-106 model will enable users to plan transitions and manage the appropriate operator workflows to return the plant to maximum operating conditions and reach faster prima-target-rate conditions. With automated systems helping manage operator workflows, there will be stronger barriers to procedural deviation, with enhanced data collection, inconsistencies, and variances in procedural execution, recorded and documented," he said.

ABOUT THE AUTHOR

Ellen Fussell Policastro (efussell@isa.org) is an ISA Standards administrator. E-mail her for more information on ISA106 or to volunteer to work on this committee.