In demand-limited industries, the overarching objective is to improve utilization. This cannot be achieved without reducing unplanned downtime. Research shows that the largest reason for unscheduled downtime is operational or human error, which accounts for approximately 42 percent of the unscheduled shutdowns in the process industries. Of that 42 percent, 16 percent is directly related to procedural error.
ARC research into the future role of process control operators indicates that a high-level perspective will enable flawless intervention by exception, relieving operators of manual tasks, freeing time for more value-adding activities. The same research also identified procedure automation as one of the key process automation system functions that can support this environment of flawless intervention. The expertise and operating level of experienced operators can be incorporated into automatic sequences and used to standardize operating methods and improve the efficiency of all operators.
Machines and automation are good at repetitive functions, steady state operation and transition management. Automation provides an environment for unbroken, precise execution and linear reasoning, and can consistently implement best practices through automated procedures.
Today, operational procedures can be lumped into three primary categories—manual, prompted and automated.
In manual procedures, the operator performs the necessary actions required, either through personal experience or by following standard operating procedure (SOP) manuals. The consistency with which manual procedures are performed can vary greatly depending upon the level of experience of those carrying out the procedures. Manual procedures also call for manual record keeping, which can also vary in consistency and quality. Electronic records are preferable, but their quality can also vary depending upon the accuracy with which they are entered into the system.
提示操作procedures go one step further. Here, the procedures are implemented in the process automation system and the operator is prompted to acknowledge that each step has been successfully completed in order to continue. Prompted procedures make it easier to keep electronic records and verify that procedures were followed correctly. They can also decrease both transition times and product variability.
Reduce variability
像促使操作程序,自动的公关ocedures are implemented in the process automation system. The difference is that automated procedures will go through the entire operational sequence before stopping, unless either the operator or the system intervenes on an exception basis. Automated procedures can further reduce transition times and variability.
Major operational incidents are usually the result of a confluence of factors, all converging at the same time to create an environment outside of the normal pre-operations testing environment. Most recent incidents in the process industries have some sort of procedural element associated with them. Either correct procedures were not followed, or standard operating procedures were not defined. Many procedures in the process industries tend to be manual or guided procedures. While there is a place for these, the process industries can benefit greatly from a drive to automate many critical procedures, such as start-up and shutdown.
The need for a procedural automation standard increases as the workforce continues to lose the highly experienced personnel who understand these procedures, and there is no meaningful way to capture that knowledge to guide future operator/maintenance actions properly to prevent incidents. With strong support from the process automation end-user community, the International Society of Automation (ISA) recently formed the ISA106 standards committee to address this issue.
Larry O’Brien,lobrien@arcweb.com, is Research Director at ARC Advisory Group Inc., in Dedham, Mass.
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