What is Advanced Process Control (APC) & Online Optimization?

By Peter Reynolds

Category:
Industry Trends

Process manufacturers have been using advanced process control (APC) and online optimization technologies for several decades. Advances are being made on the business front, increasing manufacturers’ needs to simplify systems on open computing platforms, and robust representation of the plant or plants. As such, one of their most pressing challenges lies in the efficient deployment and sustainment of assets with minimum human resources so that plants can effectively respond to new opportunities with-out compromising quality and profitability.

Meanwhile, the escalating complexity of technology and advances in com-puter hardware, operating systems, networking technology, programming tools and languages, and database technology keep suppliers striving to develop products to simplify solutions to satisfy the requirements of end users. In addition, the Cloud and Internet is redefining the use and de-ployment of these tools, thus influencing how the online optimization business is conducted. Balancing these dynamic forces in the market cre-ates uncertainty among suppliers and end users alike.

Key Product Classifications 

In recent years, intensified global competition has placed severe pressure on companies to shift their focus from purely growth to agile operations and sustainable long-term profitability. To reduce costs and operate more efficiently, manufacturers often use APC and online optimization tools. In fact, virtually all process industry segments use APC and online optimiza-tion tools to some degree, albeit some more than others.

Advanced process control and online optimization software suppliers come from a wide range of commercial origins. Several represent the commercial-ization of technologies developed at universities. A few represent commercial spin-offs from user industry consortiums. Many engineering firms that focus on the application of advanced technology to the process industries have developed simulation and optimization tools to help deliv-er their application knowledge. Control suppliers looking for growth opportunities embrace the process simulation and optimization software markets through in-house development efforts, by acquiring established suppliers, or in some instances, both. Operating companies with in-house expertise have developed their own APC and online optimization software, but generally do not offer their solutions for external sale.

Advanced Process Control (APC)

Advanced process control includes model-based software that is used to direct the process operation and is commonly referred to as multivariable predictive control (MPC) or model predictive control. These applications require that the process model created accurately represents the process dynamics. Improved economics of the operation or production improve-ments are typical driving forces for using these applications. Advanced process control software may include:

  • Offline and online model building, model verification, and data analy-sis tools that ensure model accuracy
  • Driver software to collect historical data from control systems or online process historian systems
  • Operator guidance to advise where the APC is taking the process
  • Prediction of controlled variables based on future planned moves of manipulated variables
  • Run-time APC tuning to adjust for changes in process dynamics with-out having to rebuild the model
  • APC controller monitoring and performance analysis software, and not the PID or process controller tuning and related performanceAPC and Optimization Process Model

Online Optimization 

Online optimization is designed to continuously monitor the state of the process and, through model reference, predict an optimum operation path. Online optimization software typically employs technology for solving

simultaneous equations. The model is a part of an application package that presents the best direction for the process operation to ensure that the ob-jectives are met. The output of the optimization software can be presented in an advisory fashion to the operator, or can be set as a new target to a lower-level control strategy or MPC control strategy. Improved economics, business performance, safety, or environmental concerns are the typical driving forces for using these applications. Optimization software packag-es may contain:

Model building application from first-principles or empirical methods

  • Simultaneous equation-solving technology
  • Methods to find optimum for non-linear process
  • Support software for "what if" and other analysis
  • Online data reconciliation methods
  • Links to raw material, intermediate product, and finished product cost information

Advanced Process Control (APC) & Online Optimization Related Reports

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