Maintenance excellence and reliability have become prominent within the corporate agenda. This is particularly true of the biopharmaceutical industry where such concepts are becoming more widely adopted in attempts to reduce risk and reduce costs. Many techniques, however, are still in their infancy, and while leaders are pressing for wider adoption, organizations are often slow to adopt these techniques because many of the new concepts are counter-cultural.
This article focuses on common misconceptions that can be encountered by those spear-heading the change and introduces some of the key concepts behind reliability engineering. This article also summarizes a detailed white paper created by the authors (1).
MISCONCEPTION: PREVENTIVE MAINTENANCE CAN PREVENT ALL FAILURESFailure is an unfortunate fact of life. Systems have a natural tendency to break and wear out, and the components of any asset are subject to the effects of wear and tear. Eventually, components fail. It is a common misconception that simply because preventive maintenance is employed, the risk of failure can be eliminated. While preventive maintenance can reduce the risk of failure, so long as the failure mode exists, the risk of failure remains.
By understanding the failure mode, appropriate maintenance strategies can be established to help detect, prevent, or mitigate failure and improve the reliability of a component. Nevertheless, 100% reliability can never be guaranteed in reality so long as the failure mode still exists.
MISCONCEPTION: ALL PREVENTIVE MAINTENANCE IS TIME-BASED
Historically, the biopharmaceutical industry has adopted mainly time-based maintenance but, in fact, other more effective strategies can often be used. Increasingly, the industry is adopting predictive and condition-based techniques to anticipate failure ahead of time. These techniques enable repairs to be planned and scheduled in a controlled manner, well before failure. Preventive maintenance can be divided into three categories:
In the biopharmaceutical industry, vibration monitoring of bearings, motors, and gearboxes in plant and equipment is increasingly common practice, where an increase in detected vibration can be used to indicate failure. Such systems provide a step increase in reliability compared to invasive time-based replacement. Similarly, thermography can be used to monitor the condition of electrical controls to signal early onset of failure. On the manufacturing floor, visual inspections carried out by operators provide early signals as part of a structured total productive maintenance system.