Conquer the Next Level of Modernization

By Randy Fischer, Market Development Lead - Paper & Wood Products, Rockwell Automation

Modernizing industrial automation and control equipment, including distributed control systems (DCSs), is a worthwhile endeavor. But, it can be a significant capital expenditure (CapEx) investment. As a result, manufacturing leaders tend to maintain and sustain automation platforms for a long time — often until the platform reaches an obsolete life-cycle status. It’s not uncommon to find a facility that still operates systems installed more than 35 years ago.

However, holding on to legacy systems beyond a reasonable point of sustainability negatively affects the business. For instance, multiple factors affect equipment reliability, including subcomponent lifespan, exposure to harsh environments and field wiring or cabling connections that loosen over time.

As equipment reliability decreases, the ability for personnel to support, maintain and sustain the equipment also becomes increasingly challenging. When a failure occurs, workers might have difficulty finding replacement parts, and they might lack the legacy system knowledge or bandwidth to provide efficient support for events that negatively impact production.

When Equipment Fails

Equipment failure can lead to significant downtime and potentially create risky environments for workers. For example, electrolytic capacitors, found in power supplies, dry up and fail over time. Older equipment has a finite lifespan. New equipment either doesn’t have electrolytic capacitors or has some designed with improved longevity, which greatly increases equipment life expectancy and prolongs the point of failure.

Some environments contain highly corrosive gases such as hydrogen sulfide. These gases accelerate corrosion and are especially damaging to any exposed electrical components and connections that don’t have conformal coating or other means of protection. And field wiring and cabling connections can loosen over time and insulation becomes brittle, which can lead to signal loss and I/O card damage.

Often, these types of issues can surface intermittently, causing a system failure that then self-corrects, making it challenging and time-consuming to troubleshoot the cause.

These situations can be avoided and, in some cases, eliminated completely with proper maintenance and equipment updates. A caveat, however, is that even if some replacement parts or recondition services are available to fix individual issues, a systematic failure might be irrecoverable or take an extended amount of time for full sourcing.

For example, a piping failure in an adjacent room or a fire in a DCS rack room can result in months of total business loss.

Modernizing to a new platform resolves these types of process reliability risks, and helps facilities improve operations to drive business outcomes and remain competitive.

Modernization Improvements

Modern technological solutions typically include benefits such as:

• Increased production.
• Improved plant-wide processes and visibility.
• Reduced raw material usage.
• Improved energy efficiency.
• Disparate data sources brought to one screen.
• Reduced unscheduled downtime.
• Fewer safety incidents.
• Less overall spare parts needed.

When implementing a new DCS platform in each area of a facility, the modernization process requires a logical plan. This is because it often carries other responsibilities, such as training personnel, adding a new centralized server or data center or designing a facility network. An upfront plan helps define the interfaces to any remaining legacy DCS or other systems.

To get the most from modernization, consider two strategies for facilities: phased migrations and rip-and-replace.

It’s impractical to consider a complete facility-wide DCS migration in a single effort unless a major process change is being implemented, such as converting from one product type to another. Depending on specific needs, even a rip-and-replace strategy can be implemented on an area-by-area approach.

Using a Phased Migration

Considering the CapEx costs typically associated with modernization efforts, many facility managers choose to implement a phased migration to distribute the cost over time and avoid or minimize extended outage requirements. A phased approach can start, for example, with migrating controllers and human-machine interfaces (HMIs) first, and then migrating I/O later as time and funds allow.

Implementing equipment over scheduled maintenance outages instead of a dedicated modernization outage can significantly reduce costs associated solely with a migration. Using proven interface solutions, a new controller can connect to legacy I/O and reduce risk and initial project implementation time.

Also, with a lesser amount of new equipment subject to rare early failure, human wiring errors or programming errors, project start-up risks decrease. As new equipment replaces old equipment, the risk of future unplanned downtime due to obsolescence is also reduced with each successive phased implementation.

Another benefit is that as equipment is replaced throughout the phases, the equipment removed from service can then be used to support any future failures of other remaining legacy equipment until it’s all transitioned.

Consider, for example, a phased migration where a large ethanol production facility used the Rockwell Automation PlantPAx^® DCS via legacy APACS field I/O. Once the controller and HMIs were migrated, the facility then was able to migrate its legacy APACS I/O to 1756 ControlLogix® I/O one process element at a time over several years. Using in-house technical resources during normal working hours drastically reduced cutover labor expenses.