Predictive Maintenance Breathes New Life into Legacy Equipment
Ian Wright posted on November 09, 2018 |

Ask anyone in manufacturing about the biggest changes in their industry and you’re almost guaranteed to hear about the Industrial Internet of Things (IIoT). The potential benefits of connecting all the assets in a factory—or even multiple factories—together under a common platform are enormous, with applications ranging from quality control to predictive maintenance.

Not so long ago, connectivity was an added selling point for industrial equipment; nowadays, it’s expected. However, this puts many manufacturers in an awkward position: What do you do with legacy equipment that can’t connect to the IIoT?

The obvious solution is to take a rip-and-replace approach, scrapping the old equipment and bringing in shiny new solutions that are bristling with connectivity. Of course, the most obvious solution isn’t always the most practical, and for many manufacturers, the idea of tearing out a machine with a proven track record is a non-starter. Fortunately, you don’t need the latest equipment to gain the benefits of the IIoT. Consider predictive maintenance, as an example.


What is Predictive Maintenance?

The concept of predictive maintenance is summed up by the old adage “An ounce of prevention is worth a pound of cure.” In other words, rather than operating on a predetermined schedule, using predictive maintenance means only performing upkeep on machines when necessary. In more precise terms, we can contrast predictive maintenance with condition monitoring: the latter simply detects wear-and-tear status while the former is more about forecasting equipment status in the future.

The idea is to detect and diagnose the conditions that predict equipment failure, enabling a more cost-effective maintenance strategy. Of course, that depends on collecting data from common machine elements, such as motors and actuators, which in turn means instrumenting those elements on older equipment.


Predictive Maintenance for Legacy Equipment

Commonly known as a “retrofit” or “wrap-and-extend” solution, there are numerous third-party options for extending the capabilities of legacy equipment. These include OPC servers, IoT platforms, IoT gateways and sensors that measure KPIs and make that data accessible to the IIoT. Properly implemented, the right IIoT system can extend the life of less productive equipment by improving OEE, possibly enough to defer or eliminate the need to replace it.

Some manufacturers with in-house networking and systems engineering capabilities can build custom solutions, but most will be better served by consulting with a system integrator and/or purchasing sensor/controller suites from a single vendor. Whatever the circumstances, the combination of lower upfront and maintenance costs, reduced downtime and better repeatability makes retrofitting the right piece of legacy equipment an appealing option.


Should You Instrument Your Legacy Equipment?

According to a recent engineering.com survey, more than half of all production activities are instrumented, if not connected. Instrumented equipment includes everything from actuators to conveyors to pumps, pneumatic and hydraulic. These systems were monitoring variables such as temperature, pressure and velocity—variables that most PLCs can already process. In other words, adding the capability to monitor these factors on legacy equipment may just be a matter of adding channels to an underloaded data system and using software to analyze performance data.

The question whether to instrument legacy equipment is really about comparing the pros and cons of a retrofit to a rip-and-replace. While this will vary by company and application, there is a broad set of advantages and disadvantages when it comes to deciding whether to retrofit a machine or scrap it.

Taking the rip-and-replace option will most likely come with a higher upfront cost, longer integration time and less customizability compared to a retrofit, but it also typically carries less baggage in terms of system maintenance and interoperability issues. In either case, manufacturers planning to increase their production data output significantly should consider installing a fault-tolerant ethernet backbone for additional bandwidth, assuming one hasn’t been installed already.


Is Predictive Maintenance Worthwhile for Legacy Equipment?

The benefits of the IIoT are numerous and obvious, but that doesn’t automatically entail that every piece of legacy equipment should be updated for Industry 4.0. There are many factors to consider when debating between instrumenting a machine and buying a new one, which is why we created a research report all about implementing predictive maintenance systems on legacy equipment.

Click here to download the report.


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