Retrofit or Upgrade: What’s Best for Your Facility?

May 16, 2022
When undertaking a controls project, beginning with an installed base evaluation can help determine if a retrofit or complete upgrade will be more advantageous in the long run.

The scope and nature of today’s controls projects are shifting. What used to be a landscape of greenfield projects now regularly includes more minor process additions and the upgrading of legacy control systems. So, how can you determine if you need a controls retrofit or a complete upgrade? An installed base evaluation may be the answer.

Start by asking why. Why does the system need to be upgraded? As your control system ages, you must identify, mitigate, and eliminate the obsolescence risks associated with a dated system. As hardware lines are discontinued and manufacturers struggle to obtain products needed for legacy modules, it becomes challenging for plants to find the replacement components needed to keep their facilities functioning. You must also consider the financial consequences of extended downtime from failed, unreliable, and obsolete hardware or software. A proactive strategy will allow you to consider options to migrate products to newer technologies that are more easily obtained and supported, ensuring that critical spares are readily available and facilities stay operational.

One way to be proactive and mitigate system failure risks is by performing an installed base evaluation. A good evaluation is more than just creating an inventory of your parts; it’s a detailed analysis of your critical plant assets and those components’ conditions. You’ll obtain lifecycle data on aging equipment, allowing you to understand what is current, outdated, or even obsolete.

An installed base evaluation should include:

  1. Field Collection
  2. Analysis
  3. Delivery of Reports/Recommendations
  4. Implementation/Remediation Processes

How do you know whether you need a retrofit or a complete upgrade? An installed base evaluation will help you decide your next best step by telling you what you have (and if it’s soon to be obsolete) and offering a plan to address problems. Knowing how much downtime you can endure, how much money you can spend, and what additional functionality you need to achieve will help you determine if you need minor updates to software or hardware components (retrofit) or if you need to physically change the entire structure of your system (complete upgrade).

If and when your control system needs to be upgraded, a design team can investigate the latest technologies and hardware solutions that best support your requirements. Technologies such as HART-enabled analog I/O modules can leverage increased capabilities in existing or new instruments. Ethernet communications allow current technologies to be used but may require cabling installations and new networking hardware. Whatever you decide, don’t forget to update your control system documentation during an upgrade.

There are many options to consider when determining how best to upgrade or replace a control system, and there is no one-size-fits-all answer. If your control system is aging and you do not yet have a plan for mitigating current or future risks, take a proactive approach and work with a systems integrator that can evaluate your facility and find the solution that meets your needs.

Where Can I Learn More?

Interstates has plant automation experts ready to help. If you have any questions about network threat detection, reach us at (712) 722-1662 or

Jamie Schmidt is a Senior Project Engineer at Interstates, a certified member of the Control System Integrators Association (CSIA). For more information about Interstates, visit its profile on the Industrial Automation Exchange.