Preventive Maintenance Won’t Solve Your Reliability Problems

Case Study

How to Improve Reliability

There is a great deal that can be done to improve reliability outside of preventive maintenance. Some of it involves the maintenance department, and some of it does not. We need to step back and look at all of the reasons why equipment fails, including the following:

  1. The way equipment is designed affects reliability.
  2. The procurement process affects reliability.
  3. The way in which equipment is transported to the site and stored on shelves affects reliability.
  4. And the way equipment is operated certainly affects reliability.

None of these activities are maintenance activities, but there are steps the maintenance department can take, including:

  1. All maintenance jobs can be properly planned and scheduled.
  2. All maintenance jobs can be performed with precision. This includes shaft alignment, belt alignment, balancing, tightening and fastening.
  3. Proactive maintenance tasks should also be performed, such as precision lubrication and frequent cleaning.

In addition, regular non-intrusive inspections should be made, and cost-effective condition monitoring tasks should be performed in order to detect when condition-based maintenance tasks are required.

Defect elimination is a name given to the proactive philosophy of looking for every root cause of equipment failure and proactively seeking to eliminate those root causes, whether they are related the maintenance department or not. This does not mean that we wait for failure to occur and then perform root cause failure analysis. Instead, we learn from industry about all the common reasons why rotating machinery and electrical and process equipment fails. Then, we act proactively to eliminate those root causes.

This is not a simple task, as it involves the majority of the people in the organization, from the highest levels of management through to operators and craftspeople on the plant floor. However, it is an important task and the only way to truly improve reliability as well as achieve the highest levels production, competitiveness, safety and protection of the environment.
Preventive maintenance has a role in industry, but it should not be the dominant strategy. The focus should be on improving the reliability of equipment at every stage of its life.

If the condition of the equipment can be detected cost-effectively, then that is the most appropriate maintenance strategy. When the failure modes are known to be age-related, and the expected trouble-free age of the equipment is well-understood, then interval-based maintenance, or preventive maintenance, is the best strategy. If the interval-based maintenance tasks and condition-monitoring tasks cannot be justified, then a run-to-failure maintenance strategy is appropriate.

Simply relying on preventive maintenance is a costly strategy that will reduce the reliability of the equipment.

This article was previously published in the Reliable Plant 2016 Conference Proceedings.

By Jason Tranter, CMRP, CRL

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