February 2020
Process Controls, Instrumentation and Automation
APC maintenance scheduling—Part 1
Advanced process control (APC) projects are supervisory programs that are often thought of as a layer of control above the base regulatory control for a process. The benefits of APC include increased throughput, reduced variation, constraint avoidance, etc., and can be combined to represent a daily economic-equivalent benefit for the application—the same anticipated benefit that led to the justification of the APC installation. Several articles report that after 18 mos–24 mos, more than half of APC installations are performing at either pre-installation levels or have been removed.1,2,3 Although diverse reasons exist for the performance shortfall, a primary reason is that the process characteristics drift from those that generated the controller model.
The Authors
Stephen M. Mayo has 38 yr of industry experience, and his research is focused on getting the most out of advanced process control. His career has included process engineering and management roles around the world in several different countries in ethylene, refining, LNG, and oil and gas production. Mr. Mayo earned an MBA degree from Oklahoma State University, where he is a chemical engineering doctoral candidate. He is also a registered professional engineer in Oklahoma.
R. Russell Rhinehart has experience in both industry (13 yr) and academics. He has served as the Head of the School of Chemical Engineering at Oklahoma State University, President of the American Automatic Control Council, and Editor-in-Chief of ISA Transactions. He is a Fellow of both ISA and AIChE, a CONTROL Automation Hall of Fame inductee, and has received numerous teaching and innovation recognitions. Dr. Rhinehart has authored textbooks on engineering statistics and nonlinear regression modeling, and engineering optimization. Now “retired,” his focus is on professional education and disseminating best-in-class techniques for modeling, optimization and control.
Sundararajan V. Madihally is a Professor in the School of Chemical Engineering at Oklahoma State University. He worked in the industry for 2 yr prior to obtaining a PhD in chemical engineering. He has published numerous articles and proceedings related to his research in tissue regeneration, as well as novel educational paradigms in biomedical engineering. Recently, he published the second edition. of his textbook, Principles of Biomedical Engineering. Dr. Madihally has received numerous teaching and mentoring awards, including the AIChE Outstanding Advisor Award.
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