Many industrial process plants are designed to run steady state for very long periods of time, thus providing a business with sustainable economic advantage. Typically, in these instances, the on-line equipment utilization will be in the high 80 to low 90 percent range. The remaining 5 to 15 percent of the available time is allocated to planned maintenance and grade changes. Because of the capital-intensive nature of these plants and processes, each percent of on-line time can represent hundreds of thousands of dollars in profits. However, while a commendable goal, it can be exceedingly challenging to maintain steady-state operations day after day. Both planned and unplanned abnormal or non-steady state events often can and do occur, hence alternative procedures must be in place to mitigate and minimize the costly associated downtime.
The ISA106 procedural automation standard provides an implementation approach for continuous processes that addresses different modes of operation beyond steady-state conditions. Assuming sufficient sensing and controller devices are installed, ISA106 provides a means to automate transitions during both steady-state (normal) and non-steady-state (abnormal) operations or process states.
ISA 106 Complements Digital Industrial Operations Procedures
Without adequate instrumentation and automation, field sensing instruments and control devices, such as valves and motors, must be read and actuated manually using an established and documented standard operating procedure (SOP). Though the form and substance of manual procedures has evolved through each of the Industrial Revolutions (1-3), today, with the advent of the Fourth Industrial Revolution (Industry 4.0), there’s still often an asynchronous relationship between the manual procedures executed in the field and the level of process automation deployed. As these manual SOPs become digitalized, ISA106 can complement the digital transformation.
In the continuous process industries, these digitalized SOPs typically involve utilizing the second-by- second, deterministic execution capability of a DCS or PLC. When configured as state-based control applications utilizing the ISA106 procedural automation standard, these operational states of the process equipment can be used as both flags/triggers and safety guards/interlocks to properly execute non-steady-state activities requiring manual procedures.
Using Industry 4.0-based technologies related to mobility, networking, security, augmented reality, and virtualization, manual procedures can be digitally transformed to help field operators execute transitions using non-electronically connected devices. In these situations, the operator becomes the “virtual I/O.” Previously asynchronous manual tasks can now be coordinated in real time with the equipment process states in the existing process control platform. Permissives created as a result of completed manual actions can be issued from the field and escorted into the real-time, ISA106- conformant application to communicate, report, and enable automated actions; thus eliminating potential operator error.
ISA106 applications are effectively an advanced form of adaptive control where alternative process control logic and associated control parameters are selected during runtime based on continuous monitoring of a unit relative to the equipment process states. This technique can be deployed for normal process event management such as filter changes/swaps, or clean-in-place. It can also be utilized for abnormal events, such as duty standby cutover of a redundant pump as the result of equipment failure.
In both normal operation-run modes, and during process startups and shutdowns, an ISA106 application can be supplemented with mobile procedure inputs to ensure human-machine synchronization. This can result in improved process safety, first-pass prime quality, and on-line asset availability of a continuous process. Businesses that operate continuous processes should strongly consider transforming their manual procedures into a digital format that can be integrated with an existing process control system to improve excellence in operational performance.
Industry 4.0 introduces new technologies that can be deployed to address the synchronization issues between humans and machines to improve operational performance by minimizing human error while executing manual tasks. A recent ARC Strategy Report highlights the trend toward . ARC clients can contact their ARC client manager to obtain a complete copy of this report.
About the Author
Mike Williams has over 40 years of experience in process automation in the chemical industry. Mike provides technological and business work process guidance in the automation and operation of batch and continuous chemical processes. His most recent emphasis has been on manufacturing IT asset management, system End of Life assessment, and migration.
Prior to becoming a consultant and ARC Associate, Mike worked for The Dow Chemical Company in the Specialty and Advanced Materials Divisions, where he consulted on and provided front end loading assistance and investment planning to a number of DCS and MES projects.