Control magazine had a great article a few months back entitled, Control System Migration. It did a great job covering the selection and planning process when modernizing your automation system. Recently, I featured Emerson’s John Dolenc and his perspectives on justifying your automation modernization investment. Taken together, there are many ideas to help plan a system migration project.
John sent me an email with his thoughts on the Control magazine migration article. With his writing prowess, I like to kid John that he should also be an Emerson blogger. In that spirit, I’ll include his thoughts in their entirety:
I just recently read an article on control system migration best practices. The article noted that the keys to a successful migration project include:
- Selecting the best control system
- Performing a Front End Engineering study to well define the project issues, develop the automation plan, and develop detailed scope of works and cost estimates.
- Using experienced engineering services and following detailed procedures during the detailed design and implementation phase.
- Developing a detailed cutover plan
I agree with the noted engineering procedures, especially the need to conduct Front End Engineering to properly scope and design the migration. However, the article approached the system selection process from solely a technical performance issue from a configuration engineer’s / system integrator’s viewpoint. The author defined a system selection process that rated system suppliers on controllers, I/O modules, operator consoles and other system hardware/software issues.
Conducting a technical evaluation of a control system is always advisable, but this evaluation is best done prior to any identified project as an exercise to create an approved bidders list. One must also expand the criteria to include new technologies that are found in today’s state-of-the-art control systems; especially those technologies that may provide the financial benefits to justify a system migration. Interface capabilities to ERP systems, asset management systems, and the ability to easily incorporate new field communication technologies such as fieldbus and wireless are important to future systems. We always need to remember that a control system is a tool to be used by operations to efficiently run the process on a day-to-day basis. The availability of tools to monitor control and process performance is important. How easily control strategies can be updated, including advanced control techniques, is important for continuous process improvement.
The article began with the assumption that the decision has been made to update the existing control system. No mention was made for the engineering team to review what led to the decision to replace the existing control system. It is vital for the engineering team to understand the financial and operational reasons for replacing the system. The control system issues that led to the replacement must be identified. And it is the ability to best meet these operational and performance issues that should dominate the system selection process.
The operational objectives must also be considered when developing the automation plan. The results from a replacement-in-kind of the existing control system will typically never please plant and operational management. Correcting process performance issues normally involves improving process measurements, correcting poor control valve performance, implementing better control loop strategies, improved interlocking strategies, sequential control strategies and possible advanced control strategies.
@JimCahill good post. I like the point about technical evaluation of the control system. Our vendor comp analysis looks @ 600+ criteria