Maintenance philosophies have come a long way in the last few decades.
In the beginning there was reactive maintenance, i.e. only fixing something if it breaks or causes a problem. That's the way I treated my first car. I was a good customer of tow trucks. At one time neither the fuel gauge nor the odometer worked, and I kept a running estimate of the approximate distance traveled since the last fill-up. It wasn't a perfect system. I once ran out of gas late at night and had a long walk home.
Imagine maintaining a paper mill only using a reactive maintenance philosophy. It would be a disaster!
Preventive maintenance, which was the next trend to emerge, involves systematic inspection of equipment, usually time-based, detecting and correcting any potential failures either before they occur or before they develop into major defects. I had to check the oil on that old car regularly, and kept a gallon of motor oil in the trunk so I could top up the oil regularly, until I had a valve job done in order to pass mandatory emission testing.
As advanced inspection techniques emerged, an even better philosophy came along, that of Predictive maintenance. The concept is something like "the squeaky wheel gets the grease", as opposed to oiling all wheels equally at regular intervals; except that predictive maintenance uses advanced tools such as thermal imaging, vibration analysis, ultrasonic testing, and oil analysis to give early warnings as to when the performance of that wheel might start to be a problem, long before it actually starts to squeak. This allows the appropriate corrective measure to be taken to prevent the problem from occurring. When combined with low-cost data capture and storage, allowing detailed histories to be easily accessed for each piece of equipment, Predictive maintenance can be very powerful. When you are sitting on a plane that has been delayed for a minor maintenance issue, you may feel frustrated, but you should actually be thankful that the adoption of preventive maintenance and performance monitoring by the airline industry has made breakdowns in the air an extremely rare event!
The philosophy of Precision maintenance, which has not been around for very many years, takes this one step further, to pose the challenge: let's design that wheel so that it can never squeak! With very tight control of the quality of parts and tracking of operating conditions, one can design equipment whose performance remains almost the same as it ages. Some of the key aspects of a Precision maintenance philosophy are:
- Accurate fit and tolerance at the operating temperature
- Laser alignment of shafts at the operating temperature
- High quality balancing of rotating parts
- Impeccably clean lubricant
- Distortion-free equipment
- Rigid mounting and supports
- Correct torques and tensions always applied
- Only in-specification parts are installed
Adopting a Precision maintenance philosophy involves a culture change that extends to all departments – operations, engineering, purchasing and quality control must all understand the program and be part of the feedback loop.
The car I'm now driving is a lot quieter than my first car, and has had very few breakdowns, even though it's probably traveled twice the distance my first car did in its lifetime. A major reason for that is that it's been built with many of the principles of Precision maintenance in mind.
Martin Fairbank has worked in the forest products industry for 31 years,
including many years for a pulp and paper producer and two years with
Natural Resources Canada. With a Ph.D. in chemistry and experience in
process improvement, product development, energy management and lean
manufacturing, Martin currently works as an independent consultant,
based in Montreal. He is also an author, having recently published
Resolute Roots, a history of Resolute Forest Products and its
predecessors over the last 200 years.
Martin Fairbank Consulting
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