August 18, 2020

What maintenance strategy are you using?

There are two primary types of maintenance strategies: Reactive and Proactive. When determining the best possible maintenance strategy to use for your facility, many factors should be considered. For example, you need to look at asset criticality, ease of maintenance, available spare parts, and other aspects of your maintenance protocols.

Reactive Maintenance Strategy

A reactive maintenance strategy (also known as “run-to-failure”), focuses on repairing or replacing assets once they have failed. Only at that time is the asset brought back to safe operational condition.

Generally, this strategy is implemented when anticipating and preventing failure for an asset is not always efficient or effective. This strategy may make sense if an asset is identified as having little or no impact on safety, production or reputation during a criticality analysis. These assets will typically have no maintenance conducted between failures unless a technician notices a need for it.

While this approach initially seems cost effective, the inconsistent nature of breakdowns makes it hard to plan. This often results in higher than expected labor costs, significant rush parts costs, and unanticipated production losses.

PROS

  • Lower upfront costs
  • Little to no planning required

CONS

  • Hard to manage budgets
  • Shorter asset life (not running at optimal condition)
  • Higher repair costs (i.e. more severe issues)
  • Unable to plan downtime
  • Higher parts costs (e.g. rush shipments)
  • Ineffective use of labor

Proactive Maintenance Strategy

This strategy focuses on avoiding repairs and asset failure through preventive and predictive methods. The goal of proactive maintenance is to anticipate problems and prevent them from occurring. A more focused approach than reactive maintenance, proactive maintenance uses data from a CMMS, condition-based monitoring technologies, and machine sensor data to determine when asset maintenance should occur.  

Preventive and predictive maintenance have the same objective: to optimize the maintenance of assets. Like any proactive strategy, these methods can maximize asset uptime and productivity. Both approaches can be used together, but the execution of each approach is quite different.

So, what’s the difference between the two proactive approaches?

Preventive Method

Preventive maintenance is work that is regularly performed (scheduled) on a piece of equipment to lessen the likelihood of it failing. Unexpected breakdowns are avoided as work is performed while the equipment is still in working condition. Work includes cleaning, lubrication, oil changes, adjustments, repairs, inspecting and replacing parts, and partial or complete overhauls that are regularly scheduled based on time or usage triggers.

This method has an 80/20 planned maintenance ratio: 80% of maintenance initiatives should be planned while the remaining 20% can be unexpected repairs. A preventive maintenance strategy requires a significant time investment to schedule, prepare and delegate tasks, however, the efforts are more cost-effective than a run-to-failure strategy.

PROS

  • Reduces unplanned downtime
  • Cost effective
  • Maximizes productivity
  • Saves energy and resources
  • Improved reliability
  • Increases asset life

CONS

  • Doesn’t consider asset condition
  • Significant investment in time/resources
  • May result in maintenance occurring when not necessary

Predictive Method

Predictive maintenance uses condition-monitoring tools to track the condition of assets during operation. Asset failure is prevented through ongoing defect detection and operating condition adjustments. This method allows the maintenance frequency to be as low as possible to prevent reactive maintenance, without incurring the costs of preventive maintenance. The predictability and asset visibility seen with this approach ensures equipment is only shut down before an unavoidable failure. This increases an asset’s life cycle, reduces maintenance costs and increases asset availability.

PROS

  • Full visibility of assets
  • Cost effective over long term
  • Predict asset failure using data versus time

CONS

  • Requires investment in condition monitoring technologies (hardware / software)
  • Highly skilled staff needed for data interpretation

Choosing the Right Strategy

There’s no one correct approach to maintenance for everyone. It should be a balance of the various techniques based upon asset criticality and ease of maintenance at your facility.

Contact our team of reliability specialists and learn how we can help you to implement or optimize your current maintenance program.

Article by Drew MacRae, Training & Solutions Manager, Reliability