Advanced Process Control (APC) is a standard tool for process optimisation in many industries such as Refining, Chemical and Petrochemicals. There are typically many Advanced Process Control applications at each site, and a team of engineers is required to keep the APC in operation. APC performance depends on several factors such as simplicity of design, operator training, reliability of process instruments and analysers and changes in process conditions. Therefore, an APC engineer’s job is not trivial since they need to understand and correct many different aspects to ensure maximum benefits continue to be delivered. What is the best practice in APC maintenance for your Advanced Process Control applications?
Is your APC delivering benefits?
The objective of APC is typically well defined during the implementation phase. During the application’s life, process changes, lack of operator training, poor instrumentation all contribute to degradation in performance. If this performance degradation is unchecked, it will result in the APC application benefits reduced to nothing or the APC being turned OFF completely. Besides the loss in potential benefits generated by APC, there is also a big dent in operator and management confidence in the technology, which may be very hard to repair. How must APC engineers act to maintain APC applications at the best performance?
Create simple reports and conduct regular activities
APC monitoring software is available for most technologies. Besides generating reports showing APC performance, these technologies historise data that is easy to inspect in the future. The issue with APC monitoring software is that many complicated metrics are created, most of which are not understandable by operators, operations managers, and management. It is imperative that simple metrics are used to generate reports so that they are easily understood by all stakeholders. It is even better to have metrics that are directly related to a production plan.
Examples of simple metrics are yields, feed rates, product qualities, energy consumed per ton of product etc. The engineer can use detailed metrics that provide engineering insight to the controller operation for conducting maintenance activities such as model error, number of MV’s in operation, number of active constraints, etc. Once a set of reports have been set up, APC engineers should check them weekly and if there are deviations, then address them immediately. A regular dialogue with operators is required to ensure any potential issues are corrected as they come up. Besides the regular maintenance activities based on weekly reports, APC engineers should also schedule a structured review of each Advanced Process Control application with Operations management and process engineers to correct any changes that may have occurred in process conditions, strategy and instrumentation.
All stakeholders informed, wider acceptance, APC benefits maintained
Dissemination of simple APC performance reports to all stakeholders creates a common sense of understanding for all. This, in turn, creates wider acceptance and belief in Advanced Process Control applications and any future investments. The benefits of APC are maintained, helping the overall profitability of the asset.
Get more information about APC applications, and get in contact with an IPCOS control expert today. Or read the whitepaper: 'Is my plant APC ready?' to find out the requirements to start off an APC project, the refutation of commonly held misconceptions and how you can start your APC project today!
